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Electrical conductivities of pure soap-water systems

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Electrical conductivities of pure soap-water systems

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Content ELECTBICAL CONDUCTIVITIES OF PURE SOAP-WATER SYSTMS A D i s s e r t a t i o n P r e s e n te d t o th e F a c u lty o f th e G raduate School The U n i v e r s i ty of S o u th ern C a li f o r n ia In P a r t i a l F u l f i ll m e n t o f th e B equirem ents f o r th e Degree D octor of P h ilo so p h y M orris J* Heldman March 1§47 t H o This dissertation, written by M orris Heldman under the guidance of hfL&. Faculty Committee on Studies, and approved by all its members, has been presented to and accepted by the Council on Graduate Study and Research, in partial ful fillment of requirements for the degree of D O C T O R O F P H I L O S O P H Y * Dean I S A Secretary D ate......June ...194-7............ Committee on Studies Chairman TABLE OF CONTENTS CHAPTER PACE I INTRODUCTION.................... ,1 The Problem . . . . . .............................................. 1 S ta te m en t o f the Problem . . . . . . . . 1 Im portance of th e Study . . . . .- .. . . 1 Review of th e L i t e r a t u r e 3 O rg a n is a tio n of th e D i s s e r t a t i o n ..................... 6 I I a p p a r a tu s and MATERIALS............................................. 7 A pparatus ............................................................ 7 The W heatstone B r i d g e ................................... . 7 The O s c i l l a t o r and B rid g in g .................... 7 T ransform ers The N u ll- P o in t I n d i c a t o r and i t s In p u t T ransform er ................................... 15 R e s is ta n c e A r m s .................................. 19 S h ie ld in g ........................ 20 O p e r a t i o n ...................................................... 21 Accuracy of th e B ridge ......................... 21 C o n d u c tiv ity C ells .................................................. 23 S ealed G lass C e lls . . . . . . . . . 23 P lu n g e r C e ll .................................. 26 Ovens and T h e rm o sta ttin g A rrangem ents. . 29 The Oven fo r the S ealed G lass C e lls . 29 Thermos t a t t i n g Arrangem ents f o r the Plunger C e l l .................................................. 30 TABLE O f CONTENTS (C o n tin u e d ) CHAPTER PAGE M a te r ia ls . . . . . . . . 33 Sodi urn Pa I m it a t e . ........................................ 33 Sodium S t e a r a t e . . . . . . . . . . . 33 I I I CONDUCTIVITIES OF ANHYDROUS SODIUM PAL MI TATE 35 IV CONDUCTIVITIES OF SODIUM STEARATE-WATER SYSTM3 OF LO?J WATER COH T E N T ................................... 40 In S ealed C e l l s ............................. 40 P r e p a r a t io n of Samples . ........................... . 40 Conductance M e a s u r e m e n t s .............................. 42 Phase I m p lic a tio n s ....................... 67 Frequency Dependanee of C o n d u c tiv ity . . 76 I n t e r p r e t a t i o n s of th e C o n d u c tiv itie s . 78 In th e P lu n g e r C e ll ................................... 86 V CONDUCTIVITIES OF THE SODIUM STEABATE-WATER SYSTEM IN THE MIDDLE SOAP AND SOAP BOILERS* NEAT SOAP REGIONS ..................................................................103 E x p erim en tal ............................................ 103 R e s u lts above 8 0 ° ............................. 104 Phase I m p lic a tio n s a t Lower T em peratures . 110 SUM M ARY ..................................................... 113 BIBLIOGRAPHY . . ......................... 13,9 TABLE OF CONTENTS CHAPTT& (C ontinued) PACE APPENDICES 1 S3 Appendix 1, d ix 2* A method f o r D eterm ining The H a tio B^/B^ In d e p e n d e n tly o f t h e i r S e p a ra te V alues • 1E4 C a lc u la tio n of th e Amounts of W ater i n th e Vapor Phase of th e "Wire" Conductance C a l l s .................................................. 125 LIST OF TABLES TABLE NUMBER PAGE I II III IY V VI VII VIII IX X XI XII XIII XIY X V XYI XYII XYI 11 XIX XX C a l i b r a t i o n of th e O s c i l l a t o r • • • • • • . 16 S p e c if ic R e s is ta n c e s o f Sodium P a l m i t a t e . . 58 I d e n t i f i c a t i o n o f Samples of Sodium S t e a r a t e w ith Low Water C o n t e n t ...............................43 S p e c if ic R e s is ta n c e s of Sodium S t e a r a t e A • 44 S p e c if ic R e s is ta n c e s of Sodium S t e a r a t e B • 45 S p e c if i c R e s is ta n c e s o f Sodium S t e a r a t e C . 46 S p e c if ic R e s is ta n c e s of Sodium S t e a r a te I) , 47 S p e c if ic R e s is ta n c e s of Sodium S t e a r a te E . 48 S p e c if ic R e s is ta n c e s of Sodium S t e a r a te F . 49 S p e c if i c R e s is ta n c e s of Sodium S t e a r a te H . 50 S p e c if ic R e s is ta n c e s of Sodium S t e a r a te I . 51 S p e c if i c R e s is ta n c e s o f Sodium S t e a r a t e J . 52 S p e c if ic R e s is ta n c e s of Sodium S t e a r a te K . 53 C o n d u c tim etric Changes O ccu rrin g in Sodium S t e a r a t e Systems of Low Water C ontent ..................... . . . . . . . . . . . . 68 Frequency Lepenhance of C o n d u c tiv ity of Sodium S te a ra te -W a te r Samples . . .. . .. 77 R e s is ta n c e s of Sodium S t e a r a t e 0 • - • • • « 92 R e s is ta n c e s o f Sodium S t e a r a t e P . . . . . 93 R e s i s t a n c e s o f Sodium S t e a r a t e Q ..................94 R e s is ta n c e s of Sodium S t e a r a t e R ..................95 R e s is ta n c e s of Sodium S t e a r a t e S .................. 96 LIST OF TABLES (Continued) TABLE MJMBER PAGE ' XXI R e s is ta n c e s of Sodium S t e a r a t e T . . . . . 97 XXII R e s is ta n c e s of Sodium S t e a r a t e U ....................98 XXIII R e s i s t a n c e s of Sodium S t e a r a t e Y . . . . . 99 XXIY R e s is ta n c e s of Sodium S t e a r a t e W ....................100 XXV Summary of C o n d u c tim etrie R e s u lts w ith Sodium S te a r s te - W a te r Systems i n P lung er C e ll s ............................................................................... 101 XXVI S p e c ific R e s is ta n c e s o f Sodium S t e a r a t e M 105 XXYII S p e c ific R e s is ta n c e s of Sodium S t e a r a t e J S F 106 LIST OF FIGURES FIGURE HUMBER PAGE I Schematic Diagram of t h e B ridge C i r c u i t . . . . . ......................... 8 I I Schem atic C i r c u i t of th e O s c i l l a t o r and B rid g in g T r a n s f o r m e r s ......................... . 10 I I I Schem atic C ir c u it of the N ull P o in t I n d i c a t o r ...................................................................... 17 IY The P lu n g e r C e l l ......................... 28 Y S p e c i f i c R e s is ta n c e s of Sodium P a l m i t a t e ..................................................................... 39 VI S p e c if i c R e s is ta n c e s of Sodium S t e a r a t e A . 54 V II S p e c if ic R e s is ta n c e s of Sodium S t e a r a t e B ............................. 55 Y III S p e c if i c R e s is ta n c e s of Sodium S t e a r a t e C .................................. 56 IX S p e c if i c R e s is ta n c e s of Sodium S t e a r a t e D ............................................ - 57 X S p e c if i c R e s is ta n c e s of Sodium S t e a r a t e E . . . . . ......................................... 58 XI S p e c if ic R e s is ta n c e s - o f Sodium S t e a r a t e F ........................ 59 X II S p e c i f i c R e s is ta n c e s of Sodium S t e a r a t e H .................................. 60 X III S p e c if ic R e s is ta n c e s of Sodium S t e a r a te I . . . . . . . . . . . . . . 61 XIY S p e c i f i c R e s is ta n c e s of Sodium S t e a r a t e J .................................. 62 XV S p e c if ic R e s is ta n c e s of Sodium S t e a r a t e IC . . . . . . . . . . . . . . 63 LIST OF FIGURES (Continued) FIGURE NUMBER PAGE XVI Phase Diagram o f Sodium S te a ra te -W a te r . ............................................... 69 XVII S p e c i f i c R e s is ta n c e s of Sodium S t e a r a t e M ..................................................... . 107 XVIII S p e c if i c R e s is ta n c e s of Sodium S t e a r a t e U ................................................................ 108 The a s s i s t a n c e of D r. B o b e rt D. Yold i s g r a t e f u l l y acknowledged. CHAPTER I INTRODUCTION A. The Problem S ta te m en t o f th e P rob lem , I t was th e purpo se o f t h i s i n v e s t i g a t i o n (1) to m easure a l t e r n a t i n g - c u r r e n t condu ctances o f c o n c e n tr a te d soap system s a s f u n c tio n s of co m p o sitio n s, te m p e ra tu re s , and f r e q u e n c i e s , as w e l l as h i s t o r i e s o f te m p e ra tu re and p r e s s u r e ; (2) to i n t e r p r e t such f in d in g s in term s o f th e b o u n d a rie s and n a t u r e of th e p h a ses p r e s e n t i n th e system s i n v e s t i g a t e d , as w e ll as in term s o f th e n a tu r e o f th e co n d u ctan c es; (3) to c o r r e l a t e t h e s e r e s u l t s w ith th o s e o b ta in e d by o th e r e x p e rim e n ta l methods. Im portance o f th e S tu d y . The com plete e l u c id a t io n o f a phase diagram f o r th e b in a r y system o f so a p -w a te r has n o t been e f f e c t e d as y e t f o r any so ap . One of th e te m p e ra tu re -c o m p o s itio n a re a s which i s th e s u b je c t of a l i v e l y c o n tro v e rs y a t p r e s e n t i s th e one below a b o u t 100°C, and e x te n d in g over p r a c t i c a l l y th e e n t i r e co m p o sitio n 1 , 2 , 3 . ra n g e . P a r t i c u l a r l y i n th e c o n c e n tr a te d -s o a p a re a such a diagram would be q u i te im p o rta n t p r a c t i c a l l y , f o r i t would r e p r e s e n t th e changes which o ccur i n th e s o a p - k e t t l e upon c o o lin g or d ry in g , a s w e ll as th e c o n d itio n of soap i n i t s s to r a g e and u s e . A nother r e g io n which has been d i f f i c u l t to s tu d y i s th e one above 100°0 and w i t h l e s s th a n about 10$ w a te r . - 2 - F i n a l l y t h e r e a r e s e v e r a l narrow two phase re g io n s around th e c e n t e r o f th e b in a ry diagram s; t h e . p o s i t i o n s of th e b o u n d a rie s of th e s e re g io n s a r e b u t p o o rly d e fin e d from e x i s t i n g d a ta . P re lim in a ry c o n s i d e r a ti o n s and some ex p erim e n ts had i n d i c a t e d t h a t c e r t a i n p a r t s of the r e g io n s d is c u s s e d above c o u ld be s t u d i e d e o n d u c t im e tr i c a l ly . Thus i t was f e l t t h a t such a s tu d y would be a c o n t r i b u t i o n to th e knowledge o f th e phase p r o p e r t i e s of t h e t h e o r e t i c a l l y and p r a c t i c a l l y i n t e r e s t i n g so a p -w a te r system s* The d a ta o b ta in e d sho uld a ls o be u s e f u l in e s t a b l i s h i n g a mechanism or mechanisms f o r conductance i n t h e s e system s, and th u s perh aps a i d in e x p la in in g some of th e p e rp le x in g problem s e n c o u n te re d , such as th e r a t e o f o r i e n t a t i o n and g ro u p in g o f m o le c u le s, th e d i s t r ib u t i o n , of w a te r , and th e changes o c c u rrin g in th e s e p r o p e r t i e s a s a f u n c tio n of te m p e ra tu re and o th e r v a r i a b l e s . B . R eview o f th e L it e r a t u r e A lthough t h e r e a r e l i t e r a l l y h undreds of p u b lis h e d i n v e s t i g a t i o n s on t h e conducti&etrig.*. b e h a v io r o f d i l u t e system s of soaps i n w a t e r , * a s e a r c h o f the l i t e r a t u r e r e v e a ls only two s e t s o f a c c o u n ts o f such s t u d i e s on more c o n c e n tr a te d 4 ,5 system s* In t h e f i r s t a c c o u n t, M. H. F i s c h e r and M. 0 . 4 Hooker a tte m p t to e x p la in th e tem p ara tu re -co n d uctance b e h a v io r o f some c o n c e n tr a te d system s o f soap in w a te r , w ith th e main em phasis on the developm ent o f th e " s o l u b i l i t y 1 ’ h y p o th e s is a s a g e n e r a l th e o ry a p p lic a b le t o l y o p h i l i c 6 c o l l o i d a l system s# The fo llo w in g s ta te m e n t by Hartman summarizes what is meant by t h e th eo ry # . • .The e f f e c t o f tem p era tu re on a 25 p e r c en t m ix tu re o f p otassium p a l m i t a t e (o r any l i g h t m etal soap) and w a te r or a lc o h o l (or o th e r s o l v e n ts ) i s d e s c rib e d as fo llo w s . Between th e te m p e ra tu re s o f 100° and 85°G the soap i s c o n s id e re d to be d is s o lv e d in th e s o l v e n t , y i e l d i n g a t r u e homogeneous s o l u t i o n i n vshich t h e soap m olecules a r e d is p e r s e d i n the s o lv e n t and in which a c o n d itio n o f d i s c r e t e d i s c o n t i n u i t i e s e x i s t • . . . As t h e te m p e ra tu re i s d e c r e a s e d , . . . . the soap becomes p r o g r e s s i v e l y l e s s s o lu b le in th e s o l v e n t , w ith th e consequence t h a t t h e p a r t i c l e s o f soap g r a d u a lly assume * The two most prom inent l e a d e r s o f groups i n v e s t i g a t i n g in t h i s f i e l d a r e J . W. McBain and G. S. H a r tle y . dim ensions g r e a t e r th a n th o s e o f soap m o lecu les . . . . As the te m p e ra tu re i s d e c re a s e d . . . . , the i n t e r n a l - p h a s e p a r t i c l e s a re th o u g h t t o he so la r g e t h a t th ey tou ch one a n o th e r and f i n a l l y c o a le s c e * C on sequen tly the e x te r n a l phase becomes th e i n t e r n a l p h a s e ." The f a c t t h a t t h e r e a re sharp- " b re a k s ” i n th e c o u rs e s o f the t e m p e r a t u r e - r e s i s ta n c e cu rv es o f v a rio u s c o n c e n tr a te d s o a p -w a te r system s i s c i t e d as ev idence t h a t such systems " i n v e r t 1 1 from l y o p h i l i c ones o f soap d is p e r s e d i n w a te r t o ly oph obic ones of w a te r d is p e r s e d in soap a s the te m p e ra tu re is low ered, and v i c e - v e r s a . Many o t h e r sy ste m s, such as q u in o lin e /w a te r , p h e n o l/w a te r, g e l a t i n / w a t e r , and heavy m etal s o a p s /s o lv e n ts show a s i m i l a r b e h a v io r . The l a r g e amount o f evid en ce i n fa v o r of a " b ru sh - 7 heap" s t r u c t u r e f o r c o n c e n tr a te d so a p -w a te r system s makes the th e o ry o u t li n e d above u n te n a b le . A lso, no sy s te m a tic a tte m p t was made to s tu d y th e " i n v e r s io n " te m p e ra tu re s as f u n c tio n s of com positions o r p re v io u s h i s t o r i e s , n o r was the method o f o b t a i n i n g c o n ta c t betw een th e samples and th e e l e c t r o d e s proveid t o be a d e q u a te . Thus i t is d i f f i c u l t to se e how M. H. F i s c h e r 's work can s e rv e a s more th an an o r i e n t a t i o n f o r f u t u r e w orkers in th e f i e l d . The second c o n d u c tim e tric stu d y of c o n c e n tra te d so a p -w a te r system s i s even more in a d e q u a te in sc o p e, v a l i d i t y , 5 and la c k of d e s c r i p t i o n of e x p e rim e n ta l te c h n iq u e s . 5 S. S. B hatnagar and M. P ra sa d s t u d i e d th e c o n d u c t i v i t i e s of s e v e r a l "m olten" sodium and p o tassiu m soaps from 182°G to 207°C on b o th a l t e r n a t i n g and d i r e c t c u r r e n t b r id g e s . The soaps w ere made by n e u t r a l i z i n g f a t t y a c id s o f u n s ta te d o r i g i n , and w ere d r i e d in a n oven a t 40°C, and th e n f o r a week i n a d e s i c c a t o r over calcium c h l o r i d e . R e s is ta n c e m easurem ents w ere f i n a l l y made on sam ples p la c e d in sm a ll b e a k e rs w ith g o ld e l e c t r o d e s . The r e s u l t s can be c r i t i c i z e d on th e fo llo w in g grounds: ( l) The p u r i t y o f th e f a t t y a c i d s and th e r e s u l t i n g so ap s is u n c e r t a i n , e s p e c i a l l y s in c e S. S. B h ain agar and M. P ra sa d c la im th e y n e u t r a l i z e d the acidsrln a lc o h o l s o lu t i o n to b o th p h e n o lp h th a le in and litm u s I (2C ), Drying soaps under th e c o n d itio n s s t a t e d does not make them anhydrous, a c c o rd in g to th e p r e s e n t w r i t e r ' s e x p e r ie n c e . The very marked dependence of th e c o n d u c t iv i t y of such systems on the w a te r c o n te n t (C hapter IY) s e r v e s in i t s e l f to i n v a l i d a te alm ost c o m p le te ly a l l o f th e re su lt-s o b ta in e d by S. S. B h atnagar and M. P r a s a d . (3) N e ith e r th e ty p e o f e l e c t r o d e s , no r the method o f o b t a i n i n g c o n ta c t , i f any, was d is c u s s e d . (4) H eating samples to th e te m p e ra tu re s a t which m easure ments w ere made (182° to 207°) in a n open b e a k e r c e r t a i n l y r e s u l t e d in changes o f c o m p o sitio n , s c o r c h in g , o r b o th . Thus i t can be seen t h a t th e p u b lis h e d c o n d u c tim e tric in fo rm a tio n on c o n c e n tra te d so a p -w a te r system s is q u ite meager, and t h a t what does e x i s t is d is c o n n e c te d and i n some c ase s not v a l i d . - 6 - £ • O rg a n iz a tio n p f th e D i s s e r t a t i o n F ollo w in g th e p r e s e n t i n t r o d u c t o r y c h a p te r , the a p p a ra tu s and m a t e r i a l s used in th e i n v e s t i g a t i o n a re d e s c rib e d a t some le n g th in C h ap ter I I . The t h i r d c h a p te r c o n s i d e r s th e c o n d u c t i v i t i e s o f anhydrous sodium p a l m i t a t e , and i s fo llo w ed by two c h a p te r s about c o n d u c t i v i t i e s of sodium s t e a r a t e - w a t e r sy stem s. The f i r s t o f th e s e concerns i t s e l f w ith system s of low w a te r c o n te n t s t u d i e d by means o f two d i f f e r e n t ty p e s o f c o n d u c t iv i t y c e l l s , and r e p r e s e n ts th e major p o r t i o n o f th e problem a s f a r a s b o th e f f o r t s and f in d in g s a r e concerned. The o th e r c h a p te r o f s t u d i e s on so & iu m -ste a ra te w ater system s compares th e c o n d u c t i v i t i e s o f so ap b o i l e r * s n e a t soap and m iddle so ap , p hases n o t found a t th e low w a te r c o n c e n tr a tio n s i n v e s t i g a t e d i n th e p re v io u s c h a p t e r . A summary and b ib lio g r a p h y - C hapters VI and V II - f o llo w , and th e r e p o r t i s concluded w ith two a p p e n d ic e s • -7 - CHAPTEB I I APPARATUS AED MATERIALS A. A pparatus Measurements o f conductance w ere made w ith an a l t e r n a t i n g - c u r r e n t W heatstone B ridge* T his "bridge, diagrammed s c h e m a tic a lly in F ig u re I , as w e l l as the c o n d u ct i v i t y c e l l s and th e ovens used t o v a ry th e te m p e ra tu re of th e sam p les, a re d e s c rib e d in d e t a i l below . i* The W heatstone B ridge The o s c i l l a t o r and b r id g in g t r a n s f o r m e r s : The source of v o l ta g e f o r th e b r i d g e was a c o n ti n u o u s l y - v a r i a b le a u d io fre q u e n c y o s c i l l a t o r . S ince c o n d u c t i v i t i e s may be dependent upon the freq u e n cy a t which they a r e m easured,, i t was d e s i r a b l e to have a so u rc e o f a l t e r n a t i n g p o t e n t i a l s o f v a r i a b l e freq u e n cy and p u re sine-w ave form . The in stru m e n t t h a t was f i n a l l y c o n s tr u c te d met th e s e re q u ire m e n ts s a t i s f a c t o r i l y . F re q u e n c ie s which v a r i e d c o n tin u o u s ly from abou t 20 t o 20,000 c y c le s w ere a v a i l a b l e ; th e wave form a t a l l fre q u e n c ie s showed no n o t ic e a b l e d e p a rtu re from t h e sine-w ave form on a 5n c a th o d e - ra y o s c i ll o s c o p e . Such an in stru m e n t i s e a s i l y c a p a b le of showing a s l i t t l e as 5% d i s t o r t i o n . The m agnitude o f th e o u tp u t v o lta g e was about 20 v o l t s In to a h ig h impedence lo a d i n the m iddle range of f r e q u e n c i e s , w ith a s l i g h t drop a t both ends of th e a v a i l a b l e spectrfcm. About 1 volt; o u tp u t was a v a i la b l e i n t o a low (10 ohm) M S M S '“'IQ O O O 'O S vVW VW W V rua^o O O O O S v/WWvWV ' W ' l o 000 s vA A A A A A A /V 0 00-03 pvf'"n''^ M S xoa - 8 - lo a d . A f t e r an h a lf hour o f o p e r a tio n , th e freq u e n cy d r i f t was n e g l i g i b l e . The outp u t was matched in to th e e x te rh a l lo ad by.m eans of b r id g in g tra n s fo rm e rs to be d e s c r ib e d l a t e r i n t h i s s e c t i o n . The in stru m e n t was m o d ifie d somewhat from one -described 8 i n t h e l i t e r a t u r e and m an u fa ctu red com m ercially a t p r e s e n t . * A schem atic diagram is sho w n 'in F ig u re I I . A ll f re q u e n c ie s a re f e d b a c k d e g e n e r a t iv e l y , and1 m a d d i t i o n , the d e s ir e d freq u en cy i s f e d back r e g e n e r a t i v e l y th ro u g h a r e s i s t a n e e - c a p a e i t a n c e c i r c u i t . The l a t t e r i s v a r i e d b y means of a s w itc h in g arran gem ent in which v a rio u s r e s i s t o r s a re p la c e d in p a r a l l e l w ith a v a r i a b l e tu n in g condenser ^ 1 , 2 3 4,5 6 ,7 ,8 ,^ 1 2^* arrangem ent d e s c r ib e d i s a re si sta n c e -c a p a c ita n c e Wien B r id g e , and i s d e s c r ib e d in d e t a i l by B. H. M u lle r, B. L. Garman, and M. E. B ro z .9 I t has s e v e r a l ad v an tag es over o s c i l l a t o r s of the H a r tle y or b e a t- f r e q u e n e y t y p e s . Among t h e s e a r e th e p u r i t y o f the wave form and low er fre q u e n c y d r i f t o b ta in a b le in th e ty p e h e r e i n d e s c r ib e d . The com plete in s tr u m e n t was e n c lo s e d in a 19” x l l 1 1 x 8 3 / 4 n s t e e l bo x, to which was b o l t e d the 17” x 8 ” x 3 ” * H e w le tt-P a c k a rd Company, Palo A lto , C a l i f o r n i a , now m a n u fa ctu res in s tru m e n ts of t h i s ty p e ; t h e i r Model #200B i s com parable to th e one b e in g d e s c rib e d . At th e tim e t h e p r e s e n t i n v e s t i g a t i o n was s t a r t e d , sueh in s tru m e n ts were not com m ercially a v a i l a b l e . ^yt/re JT C i r c u i t o ~F £A p f /on o f C o m ponents on n e * t frByc) v w v ^ rtrww - 1 1 - EIGDBE I I (Continued) SCHEMATIC CIRCUIT OP THE OSCILLATOR £BD BRIDGING TRANSFORMERS D, - 4-gang 365 mmfd. h . c . condenser Cg - .000075-mfd* m idget mica C , C - l.O -m fd. 4 0 0 - v o lt 5 t u b u la r V V V C8 ' c 9 ' 8 mfd* 4 5 0 -v o lt e l e c t r o l y t i c t u b u l a r Cio* Cl:L - 16-mfd. 450- v o l t e l e c t r o l y t i c B , B - 10 megohms, l / 2 w a tt R , B - 1 .25 megohms* l / 2 2 6 w a tt (1 megohm and 250,000 ohms i n s e r i e s ) ■Bg, B - 150,000 ohms* 1/2, w a tt B4 , Rq - 20,000 ohms* 1/2 w a tt R^, - 1,80 0 ohms, 1 w a t t B10 - 500,000 ohms, l / 2 w a tt R1n - 100,000 ohms, 1/2 w a tt R ,„ - 500,000 ohms, 1/2 w a tt B ig - 100,000 ohms* l / 2 w a tt ^14 " ohms , 10 w a tts 11*15 - 40,000 ohms, 1 w a tt ^16 " 50>000 ohms, 1 w a tt - 10,000 ohms*, 10 w a tts R l8 - 25,000 ohms* 10 w a tts ®19 " ohms* 10 w a t ts BL1# BLg - 6 w a tt 1 2 0 -v o lt tu n g s te n mazda lamp T., - 580 c . t . , .50 ma.; 5 v* 3 a .; 6 .3 v .2 a . OH - 10 - hy. 65 - ma. f i l t e r choke S , S2 - 2 -p o le 6- p o s i t i o n s w itc h (o nly 4 p o s i t i o n s used) S — S . p . s . t . a . c * l i n e sw itc h - S . p . d . t . sw itc h 4 T - H adley #7562 T_ - Hadley #7558 - 1 2 - s t e e l c h a s s i s . The power su p p ly was on one end o f th e c h a s s i s (abou t a 4 ” p o r t i o n ) , and was s h i e ld e d b o t h above and below by s h e e t m etal s t r i p s runn ing a c ro s s th e w id th of th e c h a s s i s . The to p s h i e ld ex te n d ed up abo ut 5” , and was a t t a c h e d to th e f r o n t p anel of th e s t e e l box by b o l t s . The low er s h i e l d was b o l t e d to th e f r o n t and back o f t h e c h a s s i s . The s h i e l d i n g was n e c e s s a r y to i s o l a t e from th e power su p p ly , s in c e th e foam er was a t g rid p o t e n t i a l and h ig h impedance, and th u s o th erw ise would have ten d e d to p ic k up th e l i n e fre q u e n c y . F o r the same r e a s o n , t h e o s c i l l a t o r was always o p e ra te d w ith th e box c lo s e d . was i s o l a t e d from th e c h a s s i s b y i t s b e in g mounted on 3 p o r c e l a i n l e a d - i n bu sh in g s (Johnson # 5 1 ), w ith h a l f of each b u sh in g on e i t h e r sid e o f th e c h a s s i s . The tu n in g con denser s h a f t was coupled th ro u g h a m ethyl m e th a c r y la te ( l u c i t e ) r e s i n i s o l a t i n g c o u p le r to a n o th e r s h a f t w hich p assed th ro u g h th e f r o n t p a n e l . A p o i n t e r knob was mounted on th e l a t t e r s h a f t over a 1-100 d i a l b o l t e d to th e f r o n t p a n e l, ikll o th e r c o n t r o l s , in c lu d in g th e jac k s fo r th e v a r io u s o u tpu t impedance^ came out to th e f r o n t p a n e l . 10 B. Hague shows t h a t an A.C. b r id g e h a s maximum s e n s i t i v i t y when th e impedances of each o f th e fo u r arms as w e ll as t h a t o f th e in p u t and th e b a la n c e c i r c u i t ( t h a t i s , a c r o s s th e n u l l - p o i n t i n d i c a t o r ) a r e e q u a l. I t i s custom ary t o employ b r i d g in g tr a n s fo r m e rs a c r o s s th e o u tp u t f o r impedance m atch in g . An a d d i t i o n a l d e s i r a b l e f e a t u r e of such tr a n s f o r m e r s i s t h a t th e y i s o l a t e t h e o s c i l l a t o r c h a s s i s from th e b r id g e c i r c u i t proper* Two ou tp u t tr a n s fo rm e rs (Hadley #7 558 and #7562) were mounted on th e o s c i l l a t o r c h a s s i s . The #7558 was c o n n e c te d a s a step-dow n tr a n s fo r m e r, and th e #7562 as a s te p - u p ; e i t h e r tr a n s f o r m e r was c ap a b le of b e in g p la c e d i n th e cath ode c i r c u i t of th e ou tp u t tu b e by means of S^. The prim ary of each tr a n s fo r m e r had a d i r e c t - c u r r e n t r e s i s t a n c e o f a b o u t 600 ohms. In p r a c t i c e i t was found t h a t th e b rid g e was s u f f i c i e n t l y s e n s i t i v e so th a t th e in p u t impedance was n o t very c r i t i c a l * "R esistances of a b o u t 1000 ohms o r more w ere g e n e r a l l y m easured u sin g a ta p of the #7562, and th o se o f l e s s th a n t h i s f i g u r e w ith one of th e ta p s o f th e #7558* 0 was n e ce ssa zy to m a in ta in a c a p a c i t y b a la n c e betw een th e two s e c t i o n s o f cond en ser C^. The low er s e c t i o n had a much g r e a t e r c a p a c i t y to ground, so th e trim m ers on t h a t s e c t i o n were tu r n e d a l l t h e way o u t, and th e n th e trim m ers in p a r a l l e l w ith Cg were v a r i e d u n t i l smooth o s c i l l a t i o n was m a in ta in e d over a l l bands* T his was ob serv ed w ith a c a th o d e - ra y o s c i ll o s c o p e ; the a d ju stm e n t was most c r i t i c a l around th e low fre q u e n cy ra n g e . Once s e t , th e trim m ers were n o t changed. R was r a t h e r c r i t i c a l * The lo w e st v a lu e t h a t c o u ld 9 he used w ith o u t th e appearance o f d i s t o r t i o n in th e ou tp u t wave was t h e v a lu e shown, namely 1,800 ohms. An 84/6Z4 r e c t i f i e r tu b e was used b e ca u se o f i t s low fila m e n t c u r r e n t ; th e 5Y3GT tube f i r s t t r i e d produced too much h e a t and su bseq uent -1 4 - changes o f v a lu e of th e c r i t i c a l c i r c u i t components* Even w ith t h e 84/6Z4 th e s e t d r i f t e d somewhat in fre q u e n c y d u rin g th e f i r s t o n e - h a lf hour of o p e ra tio n * A f te r t h i s tim e th e fre q u e n c y rem ained c o n s ta n t w ith in the l i m i t s o f m easurement, which was e s tim a te d to “ be abou t 1f0 from th e degree of r e p r o d u c i b i l i t y o b ta in e d i n th e c a l i b r a t i o n s d e s c rib e d below . The fre q u e n c y o u tp u t o f such an o s c i l l a t o r sho u ld be 1/2TTBC, b u t s in c e th e v a rio u s r e s i s t o r s used were n ot c a l i b r a t e d , and s in c e 0 in c lu d e s any s t r a y c a p a c i t i e s , c a l i b r a t i o n was n e c e ssa ry * This was perform ed a g a i n s t a G en eral Badio Audio Frequency M eter, Type 434-B, S e r i a l #110, found to b e a c c u r a te a g a i n s t th e l i n e freq u e n cy o f 60 cycles* The method o f c a l i b r a t i o n follow s* The o s c i l l a t o r was f e d i n t o t h e in p u t o f the Meter ' and v a rio u s r e s i s t i v e l o a d s , w ith the o u tp u t of th e Meter f e e d in g in to the v e r t i c a l p l a t e s o f a 5 n o s c i l l o s c o p e . Bo h o r i z o n t a l g a in of th e o s c i l l o s c o p e was employed, and th u s t h e p a t t e r n o b ta in e d was a v e r t i c a l l i n e . The M eter was th e n Sid j u s t e d f o r minimum o u tp u t, and th e freq u e n cy read as t h a t o f th e o s c i l l a t o r a t t h a t p a r t i c u l a r s e t ti n g * From tim e t o tim e checks were m ade'as to t h e p u r i t y o f th e wave-form and d r i f t i n fre q u e n c y . The r e s u l t s o b ta in e d were s a t i s f a c t o r y , a s d e s c rib e d in th e b e g in n in g of t h i s s e c t i o n . When the e x te r n a l lo a d of th e o s c i l l a t o r was v a r i e d , th e wave-form rem ained u n d i s t o r t e d down t o 2,000 ohms a c r o s s the hig h impedance c i r c u i t , and 10 ohms a c r o s s th e low impedance c i r c u i t . - 1 5 - There was, however, an e x p ected drop in v o lta g e o u tp u t under the: lo w er l o a d s . The c a l i b r a t i o n curves o b ta in e d were su b s e q u e n tly used i n th e c o n d u c tim e tric work to c o n v e rt d i a l re a d in g s to f r e q u e n c i e s . The d a ta from w hich t h e s e curves were o b ta in e d a re l i s t e d i n Table I . D uring th e c o n s t r u c t io n of t h i s o s c i l l a t o r i t became e v id e n t t h a t w ith c e r t a i n s i m p l i f i c a t i o n s i t could be m o d ified t o be s m a ll, in e x p e n s iv e , and a d a p ta b le t o r o u t in e w ork, b u t s t i l l r e t a i n i t s s u p e r i o r i t y over o th e r ty p e s . These s i m p l i f i c a t i o n s r e s u l t e d in th e development o f an i ! o s c i l l a t o r now d e s c r ib e d in th e l i t e r a t u r e . The n u l l - p o i n t i n d i c a t o r and i t s i n p u t t r a n s f o r m e r : S ince a v e ry l a r g e number of’ m easurements w ere to be made, i t was d e cid ed to use a v i s u a l n u l l - p o i n t i n d i c a t o r r a t h e r th a n th e u s u a l clumsy headphones. The in s tru m e n t f i n a l l y developed ha'd th e fo llo w in g d e s i r a b l e c h a r a c t e r i s t i c s : f l) I t was re a s o n a b le i n s i z e , bein g mounted on an 8" x 4 ” m etal c h a s s is £" h ig h and co v ered w ith a bottom p l a t e . (2) I t needed b u t few a d ju s tm e n ts i n u se . (3) I t was n o t s e n s i t i v e t o s t r a y f i e l d s . (4) I t was powered from 110 v o l t s A.C. ■ (5) It* o p e ra te d over th e com plete u s e f u l ran g e of th e o s c i l l a t o r d e s c r ib e d . (6) I t was more s e n s i t i v e th an e arp h o n es. irg,13 Such e l e c t r o n i c i n d i c a t o r s have been used p r e v io u s ly . W ith th e se as a s t a r t i n g p o i n t , th e in stru m e n t s c h e m a tic a lly diagrammed in F ig u re I I I was develo p ed . A d e s c r i p t i o n f o llo w s . The power su p p ly was th e u s u a l r a d io typ e w ith -1 6 - TABLE I CA1IBRATI0E OF THE OSCILLATOR D ia l Frequency - O yoles/Second S e t t i n g Bange 1 Range 2 Bange 3 Range - 0 below 19 163 1295 7"8'30' 10 20 . 7 1 9 1 .5 1520 9^L50 BO 24.9 222.5 1825 11,050 SO 29.8 274 2275 13,500 40 3 6.4 337 2800 16,650 50 44.1 415 3480 22,000 60 53.6 518 4370 — 70 66.2 655 5520 — 80 82.6 839 7120 — 90 103.5 1085 9280 — 100 1 19.2 1250 1Q800 — A To o r X l7 ^ut tff fn/fj’ c i r c u i t _ C I Ra To h e a te r ^ 6.3 v o /ts M OV. T Volts ft I* n o 3 o ■ * - o 3 n > 3 < ~ Y 0 3 3 n X rf T X < L V O ft I 'XT 0 5‘ < "f ft. n a > o t r ^ o s- ft o 5 T 1 ** O j *•&' < ■ > C ? - 0 n > a O v t \ c rf i > * I FIGURE I I I (Continued) sc h e m a t ic c i r c u it of the -1 7 a - FU1L-POIM? INDICATOR C-t, Cof C - 8 mfd. 450- -L ■ 2 6 v o l t e l e c t r o l y t i c C*, Or,, C__ - 10 mfd* 25- o * o 11 v o l t e l e c t r o l y t i c 0A , Cq» ~ *05 mfd. pap er 4 t u b u la r C , C - *1 mfd. p aper ^ 9 tu b u la r $ 1 0 - .05 mfd. p a p e r t u b u la r R^ - 35,000 ohms* 10 w a tts B2* V Bl0* BU “ 500»000 ohms, 1 /2 w a tt ft - 150,000 ohms, l / 2 w a tt o R^, R - 500 ohms, l / 2 w a tt Rg - 40,000 ohms, l / 2 w a tt Rg - 100,000 ohms, 1/2 w a tt B , ? - 50,000 ohms volume c o n tr o l T-, - 580 c . t . , 50 ma; 5 v . 3 a . ; 6 .3v. 2 a . Tg - Thermador #1-31 CE, - 20 h e n r i e s , 50 ma• v i l t e r chokes S i - S . p . s . t . a . c . to g g le sw itch c on denser i n p u t , and f u rn is h e d a b o u t 240 v o l t s a t th e ju n c tio n of C 3 E L and C • Any s ig n a l a p p e a rin g a c ro s s th e p rim a ry o f Tg was a m p lif ie d i n cascade by th e two 6SJ7GT tu b e s , and th e a m p lif ie d s i g n a l fe d to t h e g r i d of the 6E5 " e l e c t r i c eye" tu b e . At most f r e q u e n c ie s B .^ and r e c t i f i e d th e s i g n a l s u f f i c i e n t l y so t h a t the eye c lo s e d s t e a d i l y w ith an in p u t s i g n a l; i f th e frequ en cy f e l l much below 100 cycles- the f i l t e r i n g a c t i o n of t h i s sim ple r e c t i f y i n g c i r c u i t was found to i n s u f f i c i e n t , and th e c lo s e d p o r t i o n of th e eye, wavered* Ho f r e q u e n c ie s t h i s low were used i n th e i n v e s t i g a t i o n ; however, t h i s d i f f i c u l t y could have been e lim in a te d i f n e c e s s a ry by d e sig n in g a more e f f i c i e n t r e c t i f y i n g c i r c u i t . T h e ,in p u t tr a n s fo r m e r, Tg, was a Thermador #1-31, w ith two p r i m a r i e s to match 100 or 10,000 ohms, and a high impedance se c o n d a ry . One sid e of th e in p u t was conn ected to te r m in a ls 2, 3, and 4 a s shown, and th e o th e r sid e could be connected to 1, 5 or 6 by t h e use of jacks and a p lu g . These c o n n e c tio n s gave low, medium, and h ig h impedance in p u ts r e s p e c t i v e l y . In use th e g a in of th e a m p l i f i e r was s e t b y B^, and th e n a rough minimum o b ta in e d by a d j u s t i n g th e r e s i s t a n c e b oxes. Then B-^g was s e t so t h a t th e eye alm ost c lo s e d ; a t t h i s p o s i t i o n sm ali changes in th e shadow were e a s i e r to d e t e c t . Thus a more p r e c i s e s e t t i n g o f th e r e s i s t a n c e boxes was made p o s s i b l e . S e v e ra l a l t e r n a t e a d ju s tm e n ts o f Bg and B - 1 9 - were o f te n n e c e ssa ry * a s w e l l a s grounding a d ju s tm e n ts to be d e s c r ib e d in a l a t e r s e c tio n * R e s is ta n c e a rm s: In th e schem atic diagram of th e b rid g e (F ig u re I) , R]_ and Rg would u s u a lly be one c o n tin u o u s ly - v a ri& b le s l i d e - w i r e . The n e c e s s i t y fo r approxim ate impedance- m atching of th e b r i d g e s r m s ^ and th e la r g e ran g e o f r e s i s t a n c e s e n co u n tere d i n t h i s stu d y made i t d e s i r a b l e to make p ro v is io n s f o r v a ry in g R]_ and s e p a r a t e l y . I h is was accom plished by making i t p o s s ib l e to choose 500, 5000, or 50*000 ohms a s each o f th e s e arms, a s shown by F ig u re I . N o n -in d u c tiv e p r e c i s i o n wire-w ound r e s i s t o r s w ere not a v a i l a b l e f o r t h e stu d y , so one ca'rb on w a t t / r e s i s t o r s were ch o sen f o r th e s e arm s. Since t h e r e s i s t a n c e o f th e c e l l , R , was e q u al to ^ o x x ^ g / Rn , th e a b s o l u te v a lu e s 3 C o f Rg and R-^ w© re n0^ im p o rta n t, T h e ir ratior.w as determ ined f r e q u e n t l y because th e r e s i s t a n c e s o f c arb o n u n i t s a r e bnown to d r i f t w ith time* However, the d r i f t was found to be not over a few p e rc e n t over a p e rio d of more th an a y e a r. Appendix 1 d e s c r ib e s th e method f o r d e te rm in in g th e ra ftio . The t h i r d arm of th e b r id g e , R, , c o n s i s t e d o f a box Leeds and N orthrup 9999 ohm 4-d ecade r e s i s t a n c e box* in s e r i e s w ith a 2-decad e 990,000 ohm box. The fo rm er was checked a g a i n s t a Bureau o f S ta n d a rd s 10,000 ohm r e s i s t o r and found a c c u r a te w i t h in th e l i m i t s of th e b r i d g e . One *This r e s i s t a n c e box i s l i s t e d as #4775 i n th e Leeds and N orthrup C a ta lo g . The l i m i t s o f th e v a lu e s of th e r e s i s t a n c e s a re s t a t e d a s± 0 .1 $ . - 2 0 - decade of th e l a t t e r c o n s i s t e d of 9 n o n -in d u c tiv e * 10 w a t t, ± 1 $ , 1 0,00 0 ohm r e s i s t o r s , m anufactured b y I n t e r n a t i o n a l B e s is ta n c e Company* These u n i t s w ere n o t f u r t h e r c a l i b r a t e d . The second d e cid e o f 100,000 ohm u n i t s was made from 18 i n d u c t i v e , 10 w a t t , ±10$* 50,000 ohm r e s i s t o r s . Each 50.000 ohm r e s i s t o r was c a l i b r a t e d a g a i n s t known r e s i s t o r s on a d i r e c t - c u r r e n t b r i d g e , and p a i r s chosen so t h a t t h e i r s e r i e s - r e s i s t a n c e d id n o t d i f f e r by more th a n a few p e r c e n t from 100,000 ohms. The 990,000 ohm u n it was assem bled i n a 9" x 6" x2" wooden box, the r e s i s t o r s b e in g w ired i n th e custom ary f a s h io n t o th e te r m in a ls o f a p a i r of 1 1 - p o s i t io n s in g le - th r o w s h o r t i n g sw itc h e s (1 p o s i t i o n unused) and to e x te r n a l b in d in g p o s t s . S h i e l d i n g : I t i s w e l l known t h a t a l t e r n a t i n g - c u r r e n t b rid g e s a r e s u s c e p t i b l e to s t r a y f ie ld s * Invo lved s h i e l d i n g and guard c i r c u i t s a re u s u a lly n e c e s s a r y i n measurements of in d u c ta n c e and c a p a c i t y , b ut e x p e rie n c e has shown t h a t a Wagner S h ie ld , c o n s i s t i n g o f a p o te n tio m e te r a c r o s s th e o s c i l l a t o r , w ith th e movah-le c o n ta c t grouded, i s o f te n e f f e c t iv e i n m inim izing such f i e l d s so t h a t r e s i s t a n c e measurements 14 can be made. By t r i a l and e r r o r i t was found t h a t such a s h i e l d was u n n e c e ssa ry when each of the arms was below abo u t 10.000 ohms, t h a t e f f e c t i v e s h i e l d i n g was p o s s i b l e u sin g a 50.000 ohm ra d io volume c o n tr o l f o r r e s i s t a n c e s o f t h a t o rd e r o f m agnitude, and t h a t a one megohm c o n t r o l was s a t i s f a c t o r y f o r h ig h e r r e s i s t a n c e s . These c o n tr o l s w ere in c o rp o ra te d i n - 2 1 - th e f i n a l b r id g e c i r c u i t a s shown q u ite s c h e m a tic a lly in F ig u re I . The ground In d ic a te d was a w a te r p ip e . O p e ra tio n : In u se, th e conductance c e l l (B_J foraied 1 X th e f o u r t h arm o f th e b r i d g e . A f t e r an a p p ro x im atio n o f th e r e s i s t a n c e was o b ta in e d , Bg, , th e o s c i l l a t o r b r id g in g tr a n s f o r m e r , and the n u l l - p o i n t tr a n s fo rm e r were s e t to approxim ate m atches, w ith th e k n i f e of SW^ c o n n e c te d to th e ju n c t i o n of B^ and Bg. Then was a d ju s te d f o r a minimum o f th e n u l l - p o i n t i n d i c a t o r , as i n th e s e c t i o n d e s c r i b i n g th e l a t t e r * s use (page 1 5 ). The ta p sw itc h , SW. , which allow ed c u r r e n t to flow in th e b r i d g e p ro p e r, was d e p re sse d o n ly a s needed f o r t h i s and a l l subseq uent a d j u s t ments* F ollow ing t h i s , 3W ;j_ was r e v e r s e d ; and th e p ro p e r p o te n tio m e te r , w hich was thrown i n t o th e grounding c i r c u i t by SWg, was a d ju s te d f o r a minimum of p o t e n t i a l i n th e n u l l c i r c u i t . T his l a s t o p e r a tio n p la c e d th e j u n c tio n o f and Bx a t c lo s e to ground p o t e n t i a l . Then SW^ was r e v e r s e d , a new minimum o f o b ta in e d , and th e p ro cess d e s c rib e d above r e p e a te d u n t i l c o n s ta n t s e t t i n g s were o b ta in e d f o r th e p o te n tio m e te r s e t t i n g and • Two o r t h r e e c y c le s were o r d i n a r i l y s u f f i c i e n t to a t t a i n such c o n sta n c y . With p r a c t i c e , a r e s i s t a n c e re a d in g was o b ta in a b le i n l e s s th a n a m in u te . A ccuracy o f th e b r i d g e : The p r e c i s i o n o f th e b r id g e w ith in th e l i m i t s of 100-100,000 ohms, and 100-5000 c y c l e s , was w i t h i n a fe w -te n th s of a p e r c e n t , a s judged by m easurements on v a rio u s f ix e d r e s i s t o r s . Below abo ut 100 ohms, the - 2 2 - . r e p r o d u c i b i l i t y was w i t h in a few ohms. Above 100,000 ohms o r so th e p r e c i s i o n was a l s o n o tic e a b ly p o o r e r, a lth o u g h s t i l l w i t h in a few p e rc e n t even a t one megohm. Since Bx = 3^ox ^ ^ 2 ^ 1 * and ^ 2 ^ 1 waa determinable w ith ex cellen t p rec isio n independently of the separate absolute values of B-^ and Bg (Appendix 1 ), the absolute v a lu e s of I* depend on th o se of B, _ * ]?rom what has been x box d is c u s s e d , i t i s s a fe to say t h a t betw een 100 and 100,000 ohms, and betw een 100 and 5000 c y c l e s , r e s i s t a n c e s were o b ta in e d w i t h in an a c c u ra c y of t Z < f0. £he v e ry n o t i c e a b l e q u a d ra tu re o f th e 100,000 ohm u n i t s in B makes i t n e c e s s a ry box to c o n s id e r m easurem ents above t h i s range a s u s e f u l f o r com parative p u rp o se s o n ly . Below about 100 ohms, a c c u ra c y o f ±5% was o b ta in a b le , w ith th e u s e f u l low er l i m i t a t about 20 ohms. - 2 3 - 2» Pond a c t i v i t y C e l l s . Two g e n e ra l k in d s of c e l l s i were used i n t h i s stu d y * A g l a s s tu b e w i t h two m e t a l l ic w ire s s e a le d th ro u g h i t i n to t h e b o re i s an example of one ty p e . Such c e l l s w ere s e a le d a f t e r t h e sam ples had been p la c e d i n them. The o th e r ty p e c o n s i s t e d o f a c y li n d e r of monel m e ta l, s u i t a b l y bored and i n s u l a t e d so t h a t th e c y li n d e r i t s e l f was one e le c tro d e * and a c l o s e - f i t t i n g p lu n g e r th e o t h e r . More d e t a i l e d d e s c r ip tio n s fo llo w . S ealed g l a s s c e l l s ; The f i r s t c e l l s used in t h i s i n v e s t i g a t i o n w ere made by s e a l i n g p la tin u m w ire s a b o u t .020 in c h e s in diam eter in to s o f t - g l a s s t u b e s a b o u t 6-10 m il lim e te r s in o u ts id e diam eter and 6 in c h e s lo n g . The w ir e s were f i r s t s e a le d in g la s s b e a d s , and th e beads th a n s e a l e d i n t o h o le s blow n i n th e s id e s o f th e tu b e s , fo llo w in g te c h n iq u e s t h a t a r e d e s c rib e d i n any s ta n d a r d r e f e r e n c e on 15 g la s s m a n ip u la tio n . Such c e l l s were used f o r m easuring the c o n d u c t i v i t i e s o f anhydrous sodium p a l m i t a t e . (C hapter I I I ) . Yifhen i n v e s t i g a t i o n of sam ples c o n ta in in g w a te r was s t a r t e d , i t was found t h a t c e l l s o f th e type d e s c rib e d blew up under the vapor p r e s s u r e s of w a te r a t the h ig h e r tem pera t u r e s encountered* A f te r c o n s id e r a b le e x p e rim e n ta tio n a s a t i s f a c t o r y d e s ig n to e lim in a te t h i s d i f f i c u l t y was d e v is e d . E i t h e r Kovar o r tu n g s te n e le c t r o d e s of about .020 inches i n - 2 4 - d iam ete r were u se d , th e fo rm er s e a le d i n C orning g la s s # 7 0 5 1 and th e l a t t e r i n #7.72* Two of th e s e e le c t r o d e s w ere sealed* p a r a l l e l to one another* i n a head o f th e p ro p e r gL ass, and th e head th e n s e a le d i n t o an open end of a tub e o f th e same gL ass. Most c e l l s o f t h i s type were about 6" lo n g o r i g i n a l l y , and abo u t 7 m il lim e te r s i n o u ts id e d ia m e te r , w ith w a l l s o f abo ut 0 .8 m il lim e te r s in th ic k n e s s ; -when v e r y high v ap o r p r e s s u r e s o f w ater were enco u n tered , tu b e s w ith t h i c k e r w a l l s were used* The d is t a n c e s between c e n t e r s o f th e p a r a l l e l w ire s v a rie d from about l / 4 in c h to l / 8 in c h , and th e w ire s extended i n t o th e c e l l between l / 8 in ch and 3 /8 in c h . Such c e l l s a re r e f e r r e d to as ,T p a r a l l e l - w i r e " c e l l s * The o x id iz e d s u r f a c e s of th e Kovar w ire s in th e 16 c e l l s were c le a n e d , as recommended by the m a n u fa c tu re r, w ith n i t r i c and h y d ro c h lo ric a c i d s , fo llo w e d by r i n s i n g s w ith lim e-w ater* and th e n s e v e r a l w ashings w ith d i s t i l l e d w a te r , a lc o h o l, and e t h e r b e f o r e u s in g th e c e l l s . I t was found p o s s i b l e t o c le a n th e tu n g s te n w ire s w ith m olten p o ta ssiu m n i t r i t e . A g r e a t d e a l of t r i a l and e r r o r e x p e r i m e n ta tio n was n e c e s s a ry to f i n d th e optimum c o n d itio n s under which th e oxide was removed* b u t th e e le c tr o d e s them selves n o t d e s tr o y e d . A f t e r th e tre a tm e n t w ith th e m olten s a l t , th e c e l l was p re p a re d f o r use as d e s c r ib e d f o r th e "Kovar" c e l l s above* In o rd e r t h a t r e s i s t a n c e m easurements o b ta in e d in - 2 5 - d i f f e r e n t c e l l s c o a id "be compared, and to conform to s ta n d a rd p r o c e d u r e s , a l l such measurements were c o n v e rte d to s p e c i f i c r e s i s t a n c e s * This was accom plished hy f i l l i n g th e c e l l s w ith s o l u t io n s o f a c e t i c a c i d of known c o n c e n tr a t i o n s , and m easuring t h e i r a l t e r n a t i n g - c u r r e n t r e s i s t a n c e s a t 25°C. From th e known e q u iv a le n t c o n d u c t i v i t i e s o f a c e ti c 17 acid (A ) a t various m o la ritie s (C), and the measured re s is ta n c e s o f c e lls f i l l e d with a c id was p o ssib le to c a lc u la te the s p e c ific re sis ta n c e s of the acids ” *aoid^ ’ and to define a ,T c e l l c o n sta n t” (K ) , fo r any c e l l , thus: A = i ° ° - ° - : B . = 1 0 0 0 R aoid x a 0 ld A * 0 K s ”c e l l c o n sta n t” = Scen ^ a c id I t i s e v id e n t t h a t t h e s p e c i f i c r e s i s t a n c e of any su b stan ce i n a c e l l c a n be o b ta in e d by d iv id in g th e measured r e s i s t a n c e o f t h a t s u b s ta n c e by th e ”ceQLl c o n s t a n t ” (K), o f t h a t c e l l* The d e s c r i p t i o n of each c e l l in th e d a ta of t h i s i n v e s t i g a t i o n in c lu d e s the c o n s t a n t , K, as w e l l as a d e s c r i p t i o n of the type and th ic k n e s s of g l a s s , and a s ta te m e n t of th e e le c tr o d e m a t e r i a l . The ra n g e s o f te m p e ra tu re and com po sition o f soap- w a te r system s i n w hich th e s e c e l l s c an be used to make r e s i s t a n c e m easurements a r e l i m i t e d by v a rio u s f a c t o r s . Among them a r e ( l ) th e upper l i m i t o f r e s i s t a n c e s m easurable - 2 6 - on th e b r i d g e (1 megohm), f a r t h e r l im i te d by th e high c e l l c o n s t a n t s , and (2) the observed la c k o f e le c tr o d e c o n ta c t in c e r t a i n ranges* I t was found t h a t t h e c o n d u c t i v i t i e s of th e soaps sltud.ie'd d e c re a se d r a p i d l y w ith d e c re a s in g te m p e ra tu re s and w a te r- c o n te n ts * T his o b s e r v a tio n , to g e th e r w ith th e l i m i t a t i o n s above, p re c lu d e d th e p o s s i b i l i t y of s tu d y in g soap- w a ter system s w ith p a r a l l e l - w i r e c e l l s in a t l e a s t one p r e v i o u s ly m entioned te m p e ra tu re -c o m p o s itio n re g io n o f g r e a t s i g n i f i c a n c e , namely t h a t below 100°C and below 50-60^ w a te r co n te n t* A ttem pts to stu d y t h i s re g io n le d to th e develop ment o f a c e l l d e s c rib e d below* The P lu n g er C e l l : A ttem pts to measure th e conductances o f th e c o n c e n tr a te d soaps a t e i t h e r low te m p e ra tu re s (100°0 o r l e s s ) o r w i t h l e s s th a n a few p e r c e n t w ater, o r b o th , b ro u g h t f o r t h s e v e r a l p e rp le x in g e x p e rim e n ta l d i f f i c u l t i e s * The hardness of* such samples made i t d i f f i c u l t to a t t a i n electrode c o n ta c t, and the low e l e c t r i c a l conductivity, p a r tic u l a r l y of the samples low in water content, made i t necessary to design a c e l l w ith a low c e l l co n stan t, rtKn, as defined in the previous section* Furthermore, the p ro b a b ility of lo sin g some of the w ater content during heating of the samples meant th a t an open c e l l was undesirable. I t was d ecided to a tte m p t to o b ta in e l e c t r i c a l c o n t a c t , o r a t l e a s t some r e p r o d u c ib le m easurem ents/'of r e s i s t a n c e , by a p p ly in g c o n t r o l l a b l e p r e s s u r e betw een the - 2 7 - e le c tr o d e s» The c e l l f i n a l l y developed i n an a tte m p t to acc o m p lish t h i s and t o f i l l th e o th e r needs s t a t e d i n th e p a ra g ra p h above i s drawn to f a l l - s c a l e i n P ig u re IY, which i s l a r g e l y s e l f - e s p l a n a t o r y . P r e s s u r e was a p p li e d a s needed by p l a c in g th e c e l l betw een th e p l a t e s of a C arver P r e s s w h ich was c a p a b le of p ro d u c in g p r e s s u r e s as h igh as 20,000 pounds p e r sq u a re inch* The neoprene g a s k e ts i n the c e l l were of a type used in h y d r a u lic m achin ery . The l i t t l e screw a t the top of th e low er e le c t r o d e had l e f t - h a n d e d th re a d s and was s l o t t e d . I t co u ld t h e r e f o r e be removed i n o rd e r t h a t the b o ttom e le c t r o d e c o u ld i n t u r n be p u l l e d up by means o f a p r o p e r ly - th r e a d e d rod w ith a h a n d le . The sam ples used were g e n e r a l l y under 3 m il l im e te r s i n t h i c k n e s s , and th e soap powders from w h ich th e y were formed w ere p laced i n t h e c e l l a f t e r th e s u r f a c e s to be touched by them had been th o ro u g h ly c le a n e d and r in s e d w ith a lc o h o l and e t h e r , and th e c e l l th e n d rie d i n an ov en a t 105°C. The c e l l was desig n ed t o make i t p o s s ib le to c a l c u l a t e c e l l c o n s ta n ts from i t s geom etry and th e t h i c k n e s s e s of th e sa m p les, and th u s to c o n v e rt measured r e s i s t ances to s p e c i f i c r e s i s t a n c e s . However, s in c e th e data o b ta in e d were used o n ly t o p l o t t e m p e r a t u r e - r e s is t a n c e c u rv e s , as d e sc rib e d i n Chapter IV, i t was n o t n e c e s s a r y to c o n v e rt measured r e s i s t a n c e s to s p e c i f i c r e s i s t a n c e s durin g th e c o u rse o f the i n v e s t i g a t i o n w i t h th e p lu n g er c e l l . -2 8 - S i A\r\ less S i «.«s N le o p r e n e o b be i rry p r e g r \* t t < / C <jmbr"ic in .e u tU e > ' m o i n t 4ev^ -2 9 * 3. Ovens and T h e rm o s ta ttin g Arrangements th e low h e a t - c a p a c i t y of t h e s e a le d g la s s c e l l s - made i t p o s s ib le to v a r y th e te m p e ra tu re s o f sam ples in them by h e a t i n g or c o o lin g them i n an a i r oven. On th e o t h e r hand, t h e v e ry la rg e iiestt^cap acity of th e p lu n g e r- ty pe c e l l made i t im p e ra tiv e t o h e a t or c o o l i t w i t h a l i q u i d . The d e t a i l s f o r v a ry in g the te m p e ra tu re s o f th e s e two^ types of c e l l s fo llo w : The Oven f o r th e S e a le d G lass C e l l s : T his oven had double w a l ls o f sh e e t m e ta l, and was i n s u l a t e d w ith s e v e r a l l a y e r s of a s b e s to s p aper around the o u t s i d e , a s b e s to s f i b e r betw een t h e w a l l s , and a l a y e r o f a s b e s to s paper around th e in n e r w a l l . About 35 ohms o f nichrome w ir e , wound around the in n e r l a y e r o f a s b e s to s p a p e r, se rv e d as t h e h e a t i n g e le m e n t. The oven r e s t e d on b r i c k s on t h e l a b o r a t o r y t a b l e . Two g la s s windows, f r o n t and b a c k , each ab o u t 3 in ch es by 4 in c h e s , were p ro v id e d fo r v i s u a l o b se rv atio n * The oven, was a b o u t 12 in ch es h ig h by 9 in ch es s q u a r e , and was f i t t e d w ith a w e l l - i n s u l a t e d rem ovable t o p . C i r c u l a t i o n of a i r was m a in ta in e d by an e l e c t r i c a l l y - d r i v e n s t i r r e r . The v o lta g e a c r o s s t h e r e s i s t a n c e w ir e , and th u s th e r a t e o f h e a t i n p u t , was c o n t r o l l e d by a V a ria c t r a n s fo rm e r. The te m p e ra tu re c o n t r o l p o s s ib l e by t h i s a r r a n g e ment was s u f f i c i e n t to o b ta in th e d ata d e s i r e d , a s d e s c r ib e d i n succeeding c h a p te r s . - 3 0 - I t was n e c e s s a ry to r u l e o a t th e p o s s i b i l i t y t h a t tem p era tu re g r a d ie n ts m ight e x is t i n th e oven. This was done by i n s e r t i n g the b u lb s o f s e v e r a l c a l i b r a t e d therm om eters i n t o d i f f e r e n t p a r t s o f th e volume o f th e oven. Both v e r t i c a l l y and h o r iz o n ta lly * and a t d i s t a n c e s much c l o s e r to th e w a l ls th a n any sam ples w ere su b s e q u e n tly p la c e d , ho g rad i e n t s o f more t h a n a degree or two were found to e x i s t a t any te m p e ra tu re in the range £0° - 300°C. T h e rm o s ta ttin g Arrangem ents f o r th e P lu n g e r C e l l : In u se , t h e p lu n g er c e l l was p lac ed i n a s t a i n l e s s - s t e e l c y l i n d r i c a l can* open a t th e top* and about 10 in c h e s h ig h and 6 in ch e s i n d ia m e te r. S e v e ra l l a y e r s o f a s b e s to s paper were wound around th e can f o r i n s u l a t i o n . The c e l l in the can was th e n p la c e d i n th e C arver P re ss and c e n t e r e d . C onnections were made to t h e b rid g e by a t t a c h i n g e l i p s to th e can and t o th e p lu n g e r. The can was d r i l l e d and f i t t e d w ith t h r e e c i r c u l a r lip p e d openings each ab o u t 5 /8 in ch e s i n d ia m e te r. One was v e ry c lo s e t o th e b otto m , th e .'.second ju s t.b e lo w th e h e ig h t t o which th e ja c k e t o f t h e can reached* and th e t h i r d of the r i g h t h e ig h t to a llo w a c a l i b r a t e d therm om eter .-.fitted ‘ With a neoprene s to p p e r t o ’be - in s e r te d th ro u g h ^ th e can and ' ■ * ; Vv .. i n to the c e l l a f t e r th e l a t t e r two had been a l i g n e d . The t h e r m o s t a t t i n g l i q u i d , b u t y l p h th a l B t e ; , was chosen f o r i t s low v i s c o s i t y , high b b i l i n g p o i n t , and low t o x i c i t y . I t was f o r c e d by a sm all c e n t r i f u g a l pump i n to th e a n n u la r space betw een th e can and th e c e l l . The l i q u i d e n te r e d t h i s space th ro ugh th e bottom h o le , and - 3 1 - l e f t b y g r a v i t y through, a 1 /2 in c h -d ia m e te r tu be le a d in g to th e r e s e r v o i r , which was a py rex j a r h o ld in g abo ut 2 g a llo n s o f th e l i q u i d . The tem p era tu re o f th e b a th was 18 c o n t r o l l e d by a method d e s c rib e d e ls e w h e re . I l l c o n n e c tio n s were of g l a s s tu b in g , o r neoprene tu b in g and sto p p e rs where necessary* The l a t t e r sw e lle d i n use, e s p e c i a l l y over long p e rio d s o f tim e o r a t te m p e ra tu re s above 80°C, b u t were rea so n a b ly s a t i s f a c t o r y o th e rw is e i f re p la c e d every few weeks of d a ily u se . The maximum te m p e ra tu re a t which t h e arrangem ent d e s c r ib e d was used was lOO^C. C o n tro l o f th e te m p e ra tu re o f t h e c e l l was p o s s ib l e to -0.5°C* a lth o u g h to m a in ta in te m p e ra tu re s of l e s s th a n 35°C, i t was n e c e s s a r y to p ro v id e supp lem en tary c o o lin g o f the b a t h . T his was accom plished by th e use o f a c o o lin g c o i l i n t h e b a t h th ro u g h w hich t a p w a te r co u ld be c o n s t a n t l y p a s s e d . T heptem perature of th e c e l l co u ld b e r a i s e d a s r a p i d l y as a degree every few m inutes* A lthough i t was n o t p o s s i b l e to measure th e te m p e ra tu re s o f th e sam ples d i r e c t l y , th e p ro x im ity o f the therm om eter bu lb to t h e sam ples and th e h ig h h e a t c o n d u c tiv i t y of the m etal make i t sa fe to say t h a t no a p p r e c ia b le e r r o r was made i n ta k in g t h i s te m p e ra tu re as t h a t o f the so a p s. B . M a t e r ia ls - 3 5 - I t i s r e l a t i v e l y d i f f i c u l t to p re p a re pure s i n g l e f a t t y a c id s and t h e i r s a l t s . Because of t h i s and th e p o s s ib le dependence of th e conductance of such s a l t s on sm a ll amounts of im p u ritie s * th e s o u rc e s and methods of p r e p a r a t i o n o f th e sodium p a l m i t a t e and sodium s t e a r a t e used i n t h i s i n v e s t i g a t i o n a r e d e s c r ib e d below . 1. Sodium P a lm ita te The sodium p a lm ita te used was o f th e same s to c k 19 whose p r e p a r a t i o n has been p r e v io u s ly d e s c rib e d . E. Sodium S t e a r a t e The m ajor e f f o r t s and f i n d i n g s o f t h i s i n v e s t i g a t i o n were on th e c o n d u e tim e tric b e h a v io r of sodium s t e a r a t e - w a ter sy stem s. For t h i s re a so n th e s t e a r i c a c id used was p re p a re d w ith g r e a t c a r e . The p ro c e d u re d e v ised i s now EO ' d e s c rib e d in th e l i t e r a t u r e , and th e f i n a l p r e p a r a t i o n El and d ry in g o f th e sodium s t e a r a t e i s d e s c rib e d e ls e w h e re . W ith th e e x c e p tio n o f about two grams of s t e a r i c a c id 3 y- o b ta in e d by P. F ra n c is and S. H. P ip e r , .the a c id o b ta in e d i n th e p r e s e n t stu d y i s p ro b a b ly p u r e r th an any o th e r s te a r ic a c id ever reported. The subsequent precautions ' Zl ' • tak e n in th e n e u t r a l i s a t i o n o f th e a c id , p a r t i c u l a r l y to avo id an e x c e ss o f b a se and th u s in tr o d u c e an e l e c t r o l y t i c Zt im p u rity , ' t o g e t h e r w i t h t h e degree o f p u r i t y of the a c id , make i t s a f e to say t h a t the sodi um. s t e a r a t e used i n t h i s - 5 4 - i n v e s t i g a t i o n is p ro b ab ly th e p u r e s t e v er prepared* The s ta te m e n ts above a r e p re s e n te d b e c a u se th e y may be o f some im p ortan ce w ith r e f e r e n c e to th e v a l i d i t y of th e i n t e r p r e t a t i o n s o f th e a b s o lu te v a lu e s of th e conductances o b ta in e d fo r sodium s t e a r a t e system s (C hapter lY ). CHABTSB I I I CONDUCTIVITIES OF ANHYDROUS SODIUM PALMITATE The f i r s t c o n d u c t iv i t y measurements made in th e p r e s e n t i n v e s t i g a t i o n were on anhydrous sodium p a l m i t a t e . S e v e ra l im p o rta n t f a c t s were e s t a b l i s h e d : (1) As th e tem p era tu re was r a i s e d , conductance was f i r s t m easurable w i t h th e equipment used* a t 239°C; (2) " b r e a d s 11, i n th e lo g a rith m o f r e s i s t a n c e v s. te m p e ra tu re ( ?fLRT,?) c u rv e s, as d e s c r ib e d i n C h ap ter IV, o c c u rre d s u b s e q u e n tly a t 256° and 295°; (3) a d d itio n s of l e s s th a n Vfo w a te r to th e soap low ered q u i t e m arkedly th e te m p e ra tu re a t which conductance was f i r s t m easu rab le; and (4) w i t h in re a s o n a b le l i m i t s , th e same r e s i s t a n e e - t e m p e r a t u r e v a lu e s.w e re o b ta in e d upon h e a tin g and co olin g* Item s (1) and (3) showed t h a t th e c e l ls , and equip ment used w ere s u i t a b l e f o r stu d y in g c o n c e n tra te d system s o f soap in w a te r, p a r t i c u l a r l y a t h ig h e r t e m p e r a tu re s , b u t a l s o a t low er te m p e ra tu re s a f t e r a d d it i o n s of sm a ll p e rc e n ta g e s o f w a te r . Item s (2) and (4) f u r t h e r showed t h a t d a ta o b ta in e d i n such s t u d i e s c o u ld be used f o r p h ase-chang e i n t e r p r e t a t i o n s , s in c e 256°, and 295° a g re e *In th e p r e lim in a r y s e t o f ex perim ents th e so u rc e o f v o lta g e f o r t h e b r id g e was an 1000 cy cle microphone hummer (G eneral Badio Type 2 1 3 ), th e n u l l - p o i n t i n d i c a t o r a p a i r o f e a rp h o n e s, and Bq and B 2 a s l i d e - w i r e o f a s t u d e n t- t y p e p o te n tio m e te r (Leeds & N o rth ru p #7651). - 3 6 - w e l l w ith p r e v i o u s ly e s t a b l i s h e d phase t r a n s i t i o n s a t n o 18 253u and 296 . D e t a i l s of the e x p e rim e n ta l work f o 11 ow. Sodium p a l m i t a t e powder, p r e v io u s ly d r i e d to c o n s ta n t w e ig h t, and k e p t i n a c lo s e d w eighing b o t t l e i n a d e s i c c a t o r f i l l e d with anhydrous c a lc iu m c h l o r i d e , was used t o f i l l a " w ire 1 1 conductance c e l l w ith p latin u m e l e c t r o d e s , as d e s c r ib e d in C hapter I I , to a h e ig h t of a b o u t th r e e inches* The to p was th en s e a le d o f f w ith c a re t o a v o id s c o r c h in g . S e a lin g to o k p la c e w ith in no t more th a n one m inute a f t e r th e a d d i t i o n o f the soap powder, which had been kept corked in th e c e ll* The c e l l was th e n h e a te d to about 300°0, a t w hich te m p e ra tu re 18 th e soap i s i n th e form o f a l i q u i d , and th e n allow ed to co ol in the oven to room tem peratu re* The e le c t r o d e s were b ro u g h t o u t th ro ugh th e to p of th e oven, conn ected to th e b r i d g e , and r e s i s t a n c e m easurements made a s the te m p e ra tu re was v a r i e d . T em peratures were m easured w ith a c a l i b r a t e d therm om eter, and t h e r e s i s t a n c e s o b ta in e d c o n v e rte d to s p e c i f i c r e s i s t a n c e s fro m -th e c e l l c o n s t a n t , "K" (Chapter II), of 4.33. C e ll r e s i s t a n c e s were o b ta in e d a f t e r th e oven had been b ro u g h t to a te m p e ra tu re a t which a measurement was to be made, and the oven was th e n kept a t t h a t te m p e ra tu re u n t i l a re a so n a b ly c o n s ta n t v alu e f o r th e r e s i s t a n c e was o b ta in e d . A few m inutes was s u f f i c i e n t time to a t t a i n - 3 7 - sueh c o n sta n c y a t a l l te m p e ra tu re s u se d . The d a ta , w ith the t e m p e r a t u r e - r e s i s t a n c e m easurem ents l i s t e d ch ron o l o g i c a l l y , a re summarized in Table I I , and p l o t t e d on th e custom ary "LBT" axes (C hapter lY) i n F ig u re Y. B e s is ta n c e measurements were made th ro u g h s e v e r a l c y c le s of h e a tin g and c o o lin g . The deg ree o f r e p r o d u c i b i l i t y o f th e d a ta upon h e a tin g and c o o lin g makes i t sa fe to say t h a t i f any g ra d u a l th e rm a l d ecom p osition or o x id a tio n by adsorbed a i r o c c u rre d , th e e f f e c t was to o sm all to be o f consequence i n th e p r e s e n t i n v e s t i g a t i o n . Such r e p r o d u c i b i l i t y a ls o su g g e sts th e e x is te n c e o f a d eq u a te c o n ta c t of th e soap w ith th e e l e c t r o d e s . T his q u e s tio n i s c o n sid e re d a t g r e a t e r le n g th in C hapter IT. ‘ The o t h e r c o n c lu sio n s ite m iz e d a t th e b e g in n in g o f t h i s c h a p te r a r e e v id e n t from t h e d a t a , ex ce p t f o r ite m (3). That c o n c lu s io n was e s t a b l i s h e d by opening th e c e l l , adding l e s s th a n 1fo w a te r to the anhydrous sam ple, r e s e a l i n g th e c e l l , hom ogenizing t h e c o n te n ts as d e s c r ib e d i n C h a p te r lY, and th e n m easuring th e co n du ctan ces of th e sample a s a f u n c t i o n of th e te m p e ra tu re . S ince th e d a ta o b ta in e d f o r the anhydrous sodium p a lm i ta te sample a re so s i m i l a r q u a l i t a t i v e l y to th o se o b ta in e d fo r sodium s t e a r a t e , th e i n t e r p r e t a t i o n s of th e c o n d u e tim e tric b e h a v io r of th e two a r e d e fe rre d i n t h i s r e p o r t u n t i l C hapter IY, where th e d a ta f o r sodium s t e a r a t e are p r e s e n te d . - 3 8 - T A BLE II SPECIFIC RESISTANCES OF SODIUM PALMITATE 0*0# Water - About 1000 Cycles 249 255 261 267 288 293 295 297 310 7850 1150 1 0 1 0 880 690 690 340 340 440 Measurements Obtained On Heating Measurements obtained On Cooling T°C ■ ■ v ' R-ohms T6C R-ohms 239 150M 308 350 240 90M 295 370 242 62M 291 420 243 32. 3M 288 460 245.5 18. OM 256 740 253 2550 256 760 274 855 * 256 810 281 785 253 2150 286 760 248- 9200 291 690 245 32.0M 297 645 244 50.6M 304 350 3L0 320 33.7 360 315 300 289 420 oT'e oor 0 9 ? 0 9 ? 0 0 % o ° 8 © Qjj O O r ^ f D O O 0 0 > 0 M — ?0 l*Z OH 0 o cOl1 *? U ) ~v o □ 7J •svioiysvip^^ ».re^ o d 3>* X i r o i a 9-* d « : •? » -* n j p y o d u l P ^ cl < c J 3_L ‘ P I 0 0 ' S U » p » U t j » j « j o C ^ U » UJ 3 ji n ^ P 3 J^J Q ps^p»'>>| m p»x,if ^ mil) as (3 - O O O I O ^ H % 0 ’0 o 00 0 0 0 Q 0 ;r *Dl*S Ol*\ ;0 I *? :0t "9 9 OI* I - 4 0 - CHAPTER IY GOHDUCTIYIflES OF SODIUM STEABATE-WATER SYSTEMS OP LOW WATER COUTMT A. In S e a le d C e lls 1. P r e p a r a t io n of Samples E le v en sam ples o f sodium s t e a r a t e w ith w a te r c o n te n ts ra n g in g from 0 .0 to 1 2 .8 $ were p re p a re d . A t y p i c a l p ro c e d u re fo llo w s: A " p a r a l l e l - w i r e ” c e l l , f i t t e d w ith a c o rk , was weighed and a s m a ll amount of w a te r added w ith a c a p i l l a r y p i p e t to th e bottom o f the c e l l , which was th e n rew eighed. Sodiam s t e a r a t e powder, p r e v io u s ly d r i e d to c o n s ta n t w e i g h t , w a s th e n added, and th e c e l l a g a in rew eig h ed .* The s iz e o f th e sample was g e n e r a l l y under 0 .5 gram. S e a lin g o f the c e l l was accom plished w i t h a hot flam e and a t l e a s t 4 c e n tim e te r s away from th e top o f th e sample to guard a g a i n s t "burning. Hom ogenization to o k p lao e "by h e a t i n g to t h e v i c i n i t y of 300°C i n th e oven d e s c rib e d i n *Sodium s t e a r a t e powder i s q u ite h y g ro sc o p ic . Por t h i s r e a s o n , i t was added a s r a p i d l y as p o s s ib le (th ro u g h a p a p e r f u n n e l ) , and th e c o rk r e - i n s e r t e d . A fte r th e soap powder had b e e n poured in to th e f u n n e l, a p ro c e ss w hich too k n o t over a few se co n d s, th e sample b o t t l e was c l o s e d . Then th e soap was fo rc e d th ro u g h th e fu n n e l by sh a k in g and by t h e use of a w i r e . The time of c o n ta c t of any soa$ sample w ith th e a i r o u ts id e of th e conductance c e l l was c e r t a i n l y not over two m in u te s, and p ro b a b ly l e s s th a n one m inute fo r most o f th e sam p les. As many a s s i x samples were removed from th e sample b o t t l e w ith o u t r e - d r y i n g th e powder in i t . - 4 1 - C hapter I I , and th en i n v e r t i n g the. tube .15-20 tim es by means of a rod w hich was clamped to t h e tube and was r o t a t a b l e from the o u ts id e o f th e oven. A fte r c o o lin g , th e c e l l was broken a t th e top* and a g la s s rod o f the l a r g e s t p o s s ib l e d iam ete r and le n g th in se rte d ,, a f t e r which th e c e l l was r e s e a l e d . The l a s t s te p was n e c e s s a ry to in su re t h a t no s iz e a b le f r a c t i o n of the w a te r p re s e n t i n th e system would be i n t h e vapor phase , th u s changing th e com position of th e condensed system . C a lc u la tio n s ta k in g i n to account th e v a p o r p r e s s u r e o f w ater a t th e h i g h e s t te m p e ra tu re en coun tered (300°C), t o g e t h e r w ith the assum p tion s of th e i d e a l gas law and R a o u l t 's law ,* showed t h a t th e e s tim a te d a i r space re m a in in g would c o n ta in only a n e g l i g i b l e f r a c t i o n of t h e w ater c o n te n t of any c e l l . Such a c a l c u l a t i o n is shown i n Appendix 2. The c o n te n ts of th e c e l l were th e n a g a in homogenized, and allow ed to cool i n th e c lo s e d oven to about 50° - 60°C b e fo r e b e in g removed. The r a t e o f c o o lin g was such t h a t i n a t y p i c a l e x p e rim e n t, a te m p e r a tu re of 200 °C was a t t a i n e d in abou t 20 m in utes, 150°C i n about 55 m in u te s, and 100°C i n about 60 m in u te s♦ The cover of the oven was th e n p a r t i a l l y removed, th e oven allo w ed to c o o l to about 50° - 60° i n 15 minutes,, and th e c e l l removed. *These a ssu m p tio n s, w hich a r e c e r t a i n l y f a r from c o r r e c t , a r e j u s t i f i a b l e in th e absence o f data r e g a rd in g vapor p r e s s u r e s of such s y s te m s , s in c e the c o r r e c t i o n s o b ta in e d a r e s m a ll. - 4 2 - 2. Conductanoe Measurement s S e v e ra l c e l l s were clamped v e r t i c a l l y in th e oven, and w ir e d so t h a t th e r e was one common e le c tro d e f o r th e group and an a d d i t i o n a l l e a d f o r each c e l l . The le a d s were b ro u g h t out th ro u g h g la s s tu b e s which i n t u r n were le d th ro u g h th e to p of th e oven, and th en to a te r m in a l s t r i p . The p ro p e r c h o ic e of te rm in a ls a llo w e d any c e l l i n th e oven to become f o r th e b rid g e* The c o n te n ts of th e c e l l s t o g e t h e r w ith a d e s c r i p t i o n o f the e l e c t r o d e s , th e c e l l c o n s t a n t s , and th e s i z e s o f th e tu b e s , a re shown in Table I I I . R e s is ta n c e measurements w ere made a t a s e r i e s o f te m p e ra tu re s f o r each c e l l ; f o r co m parative p u rp o se s, a l l m easurements were c o n v e rte d to s p e c i f i c r e s i s t a n c e s . Tem peratures w ere m easured w ith c a l i b r a t e d therm om eters, p la c e d a s c lo s e to th e c e l l s as p o s s ib le # S p e c if i c r e s i s t a n c e s o b ta in e d a t v a rio u s te m p e r a tu re s , t o g e th e r w ith th e f re q u e n c ie s a t w hich th e y were o b ta in e d , and th e r a t e s of h e a t in g or c o o lin g , a re shown f o r each sample i n T ables IV to X I I I , and graphed i n F ig u re s VI to XV. U n le ss o th e rw ise s t a t e d , runs were made a s th e tem p era t u r e was in c r e a s e d . The v ery la r g e r a t i o betw een th e h i g h e s t and lo w est r e s i s t a n c e s f o r most sam p les, more th a n 4 10 in many cases, n e c e s s ita te s the use of sem i-logarithm ic graphs i f the d ata fo r one sample are to be shown on one p lo t of reasonable s iz e . The data were also p lo tte d on -H 3 - TABLE HI IDENTIFICATION OF SAMPLES OF SODIUM STEARATE WITH LOW WATER CONTENT Sample No* * % Water Cell Constant Electrodes and Glass A 0*0 1,84 Kovar in 705AJ . 8 0.5 1*06 Kovar in 705AJ C 1.0 0*718 Tungstefti in 772 D 2*0 1*00 Kovar in 705AJ E 2,4 1,48 Tungsteh in 772 F 2.5 1.14 Kovar in 705AJ H 3*3 1,32 Tungsten in 772 I 4*4 1.48 Tungsten in 772 J 6.5 1.48 Tungsten in 772 K 12.8 1.84 Tungsten in 772 All ceUs were 7 nan* O* D. and about 0*8 mm* wall thickness, with the exception of cell A* The latter was about 12 mm. 0. B« and about 1*5 ram* wall thickness* *A11 samples were made using that fraction of the sodium stearate made from stearic acid characterized as batch "B1 1 in J. Philips on* s report22 on the preparation of stearic acid* TA BLE IV SPECIFIC RESISTANCES OF SODIUM STEARATE A O.Q£ Water - 960 Cycles Second Run Kept at 160° overnight; Thereafter heated about First Run Heated rapidly from room temperature to 2L0°. Thereafter heated about 1° per 3-4 minutes* T°C ^Rrohms 252 8500 254*5 1250 257*5 850 260 800 264 740 268 690 271 670 275 640 279 470 281 470 285.5 450 289.5 450 Bubbles visible until 279°. , 1 pep 3-4 minutes. T°C ' R-ohma 253 2470 256 625 260 550 263 520 266.5 485 269.5 455 273.5 450 276 420 279.5 380 283 370 287.5 350 290 350 293 335 Best ruii of thethree from the. standpoint of lack of bubbles• (Continued on Next Page) _cfif(a> TABLE IV (Continued) SPECIFIC RESISTANCES OF SODIUM STEARATE A 0«Q£ Water - 960 Cycles Third Run Kept at 240° ovemigh^* Thereafter heated about 1 per 3*4 minutes* T°C . . H-ohms T°C R*ohms 244 600u 266 520 245 360U 267 555 246 240M 268 550 247 160H •269 535 248 126U 270 535 249 77M 271 610 250 28.0« 272 485 251 13.7B 273 535 252 6300 274 530 253 3150 275 550 254 1300 276 550 255 800 277 520 256 640 278 430 257 630 279 420 258 620 280 450 259 620 280. 450 260 590 282 450 261 610 283 450 262 600 284 450 263 590 285 450 264 560 286 360 265 525 287 345 288 400 -<f5- T A B L E V SPECIFIC RESISTANCES OF SODIUM STEARATE B First. Run Heated to 285° 9 then cooled about 1° per 3-4 minutes* T°C R-ohms 284 330 277 330 273 335 269 380 265*5 380 264 330 260*5 370 257 380 253*5 400 250 425 246 530 241.5 1650 237 3400 234 6200 230 18.5H 226.5 39* 5M 222 120 M 219 230 M % % Water - 420 Cycles Second Run Kept at 140° overnight* Very erratic heating because of power line failure* T°C ff-ohas 245 1700 250 1150 255 1070 263 1000 268 930 271 930 276 400 280 330 BUbble observed around electrode up to about 270° Thir d Run Heated to 300°, then cooled about 1° per 3-4 minutes* T°C R-ohms 300 295 296 305 292 305 289 300 283.5 330 281 345 277 345 272 345 • 270 345 267 350 264.5 345 262 345 261 , 345 257.5 365 253*5 385 250 415 247 435 243 1300 240 2700 ■ * H(o" T A B L E VI SPECIFIC RESISTANCES OF SODIUM STEARATE C 1*0 Water - 960 Cycles First Run Heated rapidly from "room temperature to210°* Thereafter heated about 1 per 3-4 minutes* T°C R-ohns T°C 339 2620 i62 2L4 1540 165.5 216 1370 168 221 1060 171.5 224.5 1010 174 228.5 960 177 231.5 94) 180 235.5 920 183 238.5 910 186.5 242 910 190*5 245.5 900 193 248 890 198 251 875 201 254.5 860 204 257.5 865 206*5 260 875 210 264 860 214 268 850 218 271 490 221*5 275 470 279 475 281 480 285 490 289*5 540 Second Run Kept at 160 overnight* Thereafter heated about 1° per 3*4 minutes* R-ohms T°C R-ohms ?2*0U 225*5 650 65.3M 228*5 615 58.4M 233.5 585 53.BM 236.5 570 50. OM 240 560 44.5M 243 555 39.2M 246 600 33. BH 252*5 585 27.6k 256 605 22.0M 260 615 18.0M 263 615 11.4M 266*5 615 8300 269.5 505 5850 273.5 500 4450 276.5 485 2550 279.5 485 1370 283 490 1010 287.5 500 785 290 515 293 515 (Continued on Next Page) -f6(a)- T A B L E U (Continued) SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E C 1.056 Water ~ 960 Cycles Third Run Fourth Run Fifth Run - n . Was at room tenqperature Kept at 100°overnight. Kept at 130° overnight; for a few days. Heated Heated to 140° in 4 hours. Thereafter heated about to 100° in 1 hour, Then heated at an erratic 1° per 3-4 minutes# then about " 1° per 3-4 rate of from about 1® per minutes. 2-10 minutes, except as - _____ ■ •.____ . _______ . noted. _______ T°C R-ohms T°C R-ohms T°C R-ohms 136 223U 140 230U 142 223M 133 690M 145.5 20716 134 610M 1/3.5 245M 135 550M 143 540M 152 161U 136 53016 148 290M)* 157.5 13LM 137 490M 148.5 260k)* 160.5 1236 138 415M 158 13QM 164 108M 140 370M Then left for 167 98.016 142 340M 20J hours at 170°, 170 87.5M 144 30 5M and heated as before. 173 76.5M 146 275M 183 40.0k 176 67.5M 148.5 220M 192 23.0M 179 61.5M 151 185M 195:5 18.7M 182 53.0M 153 17016 204.5 8300)** 185.5 44.5k 155 147M 204 8600)** 188.5 38.5M 157 133M 217 1570. 191.5 31.0M 159 123M 226 870 195.5 23.0M 161 117M 236 890)* 199 16.9M 163 110k 236 850)* 202.5 11.36 165 1Q4M 205 8600 167 100M * Readings 30 minutes 209 5050 169 92.0M apart 212 2000 171 86. 0k 2L5 1640 173 81.0M ** Readings 15 minutes 218 1380 175 75.0M apart 221 1120 178 66. 0k 224.5 900 227.5 845 230 815 233 785 _in - TABLE VII SPECIFIC RESISTANCES OF SODIUM STEARATE D 2.0JC Water - 420 Cycles First Run Heated to 285°* then cooled about 1° per 3-4 minutes. T°C mmamm R-ohms 282 295 277 300 273 *5 305 269 295 266 285 264 270 261 250 257 255 254 255 . 250 265 2 2 * 6 265 2U. 5 270 237 280 234 300 230 310 226.5 350 222 360 219 360 213 360 207 1060 203 1700 199 3150 195 5050 192*5 7800 189 12.0M 182 25.0M 177*5 27.5M 174 31.015 170 35.0M 167 37.QM Second Run Kept at 140° overnight* Very erratic heating because of power line failure. Third Run Heated to 300° # then cooled about 1° per 3-4 minutes* T°0 R-ohms T°C R-ohms 146 35 .QM 300 290 151*5 28.0M 296 265 155 25.OM 293 255 158.5 22. 2M 288.5 255 162 20.011 284.5 265 165.5 17. 6U 281 260 170 14. BM 277.5 265 174 12.1M 272.5 265 229 330 269.5 275 233 330 264*5 275 236.5 320 261 265 241.5 310 258 265 245 310 253 270 250 310 250 275 254 300 247 285 263 275 244 285 267 275 240 295 271 265 236.5 305 275.5 265 233 330 280 260 228;5 350 224.5 350 219 370 213 450 209 660 206 1030 203 1700 199 2750 196 4750 192 810Q - if 7(a) ~ TABLE VII (Continued) i SPECIFIC RESI5TANGSS0F SODIUM STEARATE D 2 * 0 % Water - 420 Cycles Fourth Run o Kept at 170 overnight* Thereafter heated" about , 1° per 3*4 minutes* T?C 161 186 189*5 196*5 2 0 0 203 206 209 213 216.5 220 223 228 232 235*5 239 242 245 249 251*5 255 258 R-ohms 12.3m 1 1 . 3 M 5500 3850 2900 2050 990 670 385 360 3*0 320 315 300 300 290 285 280 275 275 [ Fifth Run Kept at 230° bvemigit* Thereafter heated about 1° per 3-4 ainut es. T°C 280*5 284 286*5 291 294 297 R-ohma 260 26$ 260 260 265 290 - V £- T A B L E V III SPECIFIC RESISTANCES OF SODIUM STEARATE E 2.4$ Water - 960 Cycles First Run Heated rapidly from room temperature to 210°. Thereafter heated about 1° per 3-4 minutes# T°C - R-ohms T°C 210 375 162 213*5 380 165*5 216 380 168 220.5 380 171*5 225 375 174 228 375 177 232 375 180 235 375 183 239 375 18? 242 375 190 246 375 193 248 375 197*5 251 375 201 255 375 204 257 375 206.5 260 375 210 264 375 214 268 260 218 271 255 221.5 275 255 225.5 279 255 281 255 285 255 Second Run Kept at 160° overnight. Thereafter heated about 1° per 3-4 minutes. R-ohms T°C R-ohms 3550 228.5 270 3150 233 255 2900 237 255 2600 240 255 2350 243 255 2000 246 275 1750 252 270 1550 256 280 1220 260 290 990 263 305 800 266 250 580 269 240 410 273 240 350 276.5 230 330 279*5 230 315 283 230 300 287 230 290 290 225 285 293 225 (con tin u ed on n ext page) T A B L E V III (Continued) SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E E 2.k% Water - 960 Cycles Third Run Kept at 130 over- night. Thereafter heated about 1° per 3-4 xainutes# Fourth Run Kept at 100° overnight. . Then heated about 1° per 304 minutes, except toward the end of / the run, as noted._____ Fifth Run Was at room temperature for a few days* Heated to 100° in 1 hour, then about 1° per 3-4 minutes. T°C R-ohms T°C R-ohms T°C H*ohms 136 7400 121*5 156M 120*5 375M 139.5 6950 123 127M 122 330M 142 6550 125 90M 123 300U 145 5950 127 63.5H 124 260M 148*5 5400 129 47M 126 195M 152 4850 131 28i5M 127 164M 157.5 4000 132 24.5M)Readings 128 149M 160*5 3650 132*5 23. 5M)15 minutes apart 130 104M 164 3300 132.5 22* 5H One hour 131 85.5M 167 2950 after 132° 132 74.5M 170 2600 reading 133 89.5M 173.5 2300 136 14.2M 20 hours 134 82. OM 176 2050 later 135 73.0M 179 1800 136 71.QM 182 1540 137 67.QM 185.5 1280 138 61.5M 188*5 1070 140 56.0M 192 860 142 45.5M 195.5 6?0 144 34.5M 199 510 146 26.0M 202 390 148.5 18.7M 205 350 151 14.9M 209 300 153 12.OM 212 310 155 9700 a5 315 157 8200 159 6850 161 5800 163 5100 165 4400 167 3750 169 3300 171 2800 173 2300 175 1950 178 1650 tim m ix SPECIFIC RESISTANCES OF SODIUM STEARATE F 2.5% Water - 420 cycles First Run Heated to 285°• then to 285 • about 1 cooled about .l~ per 3-4 minutes* Second Run ‘ •-'X T.» y.. o ' Kept at 14© overnight* Vexy erratic heating be cause of power line failure . T°C R-ohms T°C R-ohms 282 250 - 146 4000 277 250 152 3300 273.5 230 155 3200 269 210 159 2800 266 200 162 2600 264 177 166 2300 261 177 170 2050 257 173 175 1630 254 173 179 1300 249.5 173 184 940 246 173 229.5 200 24L 173 233 200 237 182 237 200 233.5 192 24L 195 230 192 245.5 190 226 202 251 190 222 205 254 190 219 210 264 190 213 210 267 200 206 230 272 240 203 250 198 280 195 400 192.5 550 181 135QO 177.5 1580 173.5 1850 170 2150 166 2450 . (Continued on Next Page) T A B L E IX (Continued) SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E F 2 * 5 % water - 420 Cycles Third Run Heated t© 300°C, then cooled about 1 per 3- 4 minutes. T°C R-ohms 300 285 296 275 293 2 4) 288.5 225 284.5 220 281 190 277.5 190 274 190 272.5 190 269.5 190 267 190 264 190 261 190 258 190 253 190 250 190 247 190 244 195 239 200 237 230 232 210 228.5 220 224.5 230 219 235 212.5 240 209 250 206 290 203 300 199 310 196 360 192 575 Fourth Run Kept at 170° overnight. Thereafter heated about jp per minutes. T°C R-ohms 178 1370 181.5 1180 186 930 190 690 193 550 197 395 200 305 203.5 295 206 290 209.5 260 213 255 216.5 245 219.5 245 223.5 240 228 240 232 225 235 220 239.5 223 242 235 245 220 249 215 251.5 215 255 210 258 210 Fifth Run Kept at 230° overnight. Thereafter heated about 1° per 3-4 minutes. R-ohms 195 195 230 280*5 284 289 291 294 297 280 - s o - TABLE X SPECIFIC RESISTANCES OF SODIUM STEARATE H 3*3$ Water - 960 Cycles First Run Kept at SO overnight* Thereafter heated about 1° per 3-4 minutes* T°C R-ohms T°C R-ohms 125 71*5M 163 3750 127 63«5M 165 3150 129 49*0H 167 2650 131 42*0M 169 2300 133 46.0M 171 1900 135 42* 0M 173 1670 137 36.5M 176 140 30*013 173 1150 142 26. 0M 180 1330 144 21*013 ,132 1QOO 146 16*513 334 930 143 13*313 136 820 154*5 7350 188 775 157 6450 190 760 159 5450 192 710 161 4600 Second Run Kept at room temperature overnigh£» Thereafter heated approximately 1 per 4 minutes* T°C R-ohms 121 84M 123 6313 125 6lM 127 52M 129 44M 131 36*513 133 33.5M 135 33.5M 137 30M 139 2613 141 23.5M 143 19*013 145 16.3M 147 12.7M 149 10.8M 151 9000 -5 -U * - T A B L E XI SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E I 4.4# Water - 960 First Run Heated rapidly from room temperature to 210°* Thereafter heated about 1 per 3*4 minutes* T°C R-ohms 210.$ 245 213 245 216.5 255 220 255 225 255 22 8 255 232 255 239 245 242 245 246 2/0 246 240 251*5 230 2 55 235 257 245 260*5 245 263.5 245 268.5 220 271 220 275.5 225 279 220 281 220 285 225 290 240 Cycles Second Run Kept at 160° overnight* Thereafter heated about 1° per 3*4 minutes* T°C R-ohms T°C R-ohi 162 680 233 200 165 635 237 195 168*5 620 240 195 171.5 570 243 195 174 525 246 205 177 480 252*5 190 180 395 257 200 187 295 263.5 210 190 255 266 210 193 245 270 210 198 245 273 210 201 240 276*5 210 204 230 283.5 200 207 225 287.5 200 210 225 290 205 214.5 225 293 205 218 215 222 210 225 205 229 200 (Continued on Next Page) - s m ~ T A B L E XI (C ontinued) SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E I 4*4$ Water - 960 Cycles Third Run Kept at 130° over- Thereafter heated about 1 per 3-4 minutes* T°C R-ohms 136 1160 139.5 1120 142*5 1080 145 1040 143.5 1150 149 1100 152 1120 153 1010 157 940 160*5; 375 164 820 167 710 170 650 173.5 575 176 530 179 470 133 415 135.5 345 133.5 300 192 270 195.5 260 199 260 202 240 Z) 5.5 230 Fourth Run Kept at 100° over night* Then heated about 1° pdr 4 min utes, except toward the end of the run, as ______noted*________ T°C R-ohms 101 560M 102 485M 103 445M 104 390M 105 360M 107 305H 109 255M 111 20 OM 113 160M 115 138M 119 138M 12L 17.2M 123 17.2M 125 16. 6H 127 14.2M 129 11.4M 131 9000 132 9200)Readingi 133 3700)15 min- )utes )apart. 132*5 8600) 0ne )hour )after )132° )reading* 136 5900)30 )hours )later Fifth Run Was at room temperature for a few days* Heated to 100° in 1 hour, then about 1 per 3-4 minutes* T°C 5-ohms 103 45014 105 37014 107 300M 109 23014 111 24014 113 23014 115 180M 116 127M 117 14214 119 8214 121 21.014 123 2 0 * 0 1 1 124 20*014 125 18*314 126 17.914 127 15.714 128 14.514 129 12. lM 130 10.814 131 9100 132 8600 133 8200 134 7700 135 7100 136 6700 137 6350 133 6050 140 5450 142 4600 144 3700 146 3050 148*5 2400 151 1950 (Continued on Next Page) S/(bj- T A B L E XI (C ontinued) SPECIFIC RESISTANCES OF SODIUM STEARATE I 4.4# Water - 960 Cycles Fifth Run (Continued) Was at room temperature for a few days* Heated to 100 in 1 hour, then about 1° per 3-4 minutes* T°C E-ohms 153 1 6 8 0 155 1 4 2 0 157 1 2 4 0 159 1 0 7 0 1 6 1 975 163 8 4 0 165 740 167 6 5 0 169 5 8 0 171 515 173 450 175 395 1 7 8 3 6 0 T A B L E XII SPECIFIC RESISTANCES OF SO D IU M STEARATE J 6.5% Water - 960 Cycles F irs t Run Second Run 0 Kept. a t 100° overnight. Heated approximately 1 per 4 M nutes, Thereafter heated'about - sta rtin g from room temperature. l° .p e r 2 minutes. T°C R-ohms T°C R-ohms T°C R-ohms 46 him in 7600 105 2150 47 373M . ns 7200 107 2060 48 3I0M H5 6500 109 1950 49 310M n7 5450 111 1820 50 300M 119 4600 113 1660 51 215M la 2250 114 1590 52 186M 123 1750 n5 1500 53 164H 125 Vffi n? 1300 55 134M . 127 1340 119 noo 57 104M 129 1120 120 1020 59 89.5M 331 895 121 910 61 67 ♦OM 133 775 122 745 63 55.0M ' 135 730 123 635 65 48.5M 137 680 125 480 67 43.5M 139 635 128 395 69 36.5M 141 575 129 390 7 3 . 31.5M 143 525 130 375 73 27 .OM 145 455 131 355 75 23* 5M 147 410 133 320 77 21. O M 149 380 135 305 79 19.0M 152 330 138 285 81 17. OM 153 305 140 260 83 15.5M 154 290 141 245 85 14.0M 155 285 144 220 87 13.2M 156 275 145 210 89 12.4M 157 ' 275 1 4 6 200 91 11.5M 159.5 285 148 185 93 11.0M 161 2?5 150 175 95 10.5M 162 255 152 155 97 10.4M 163 245 154 145 99 10. AM 164 240 156 135 101 10.2M 165 225 158 127 103 9750 167 ao 160 123 105 9400 168 190 162 127 107 8600 170 155 164 127 109 8400 172 155 174 155 - S ' 3- TABLE XIII SPECIFIC RESISTANCES OF SODIUM STEARATE K 12.8# Water - 960 Cycles I _ ^ F irs t Run ~ Second Run ’ Q Heated 'approxliiiately " Kept a t 80° overnight* " Then Heated about 1° 1 per 4 minutes, s ta rtin g per 3 - 5 minutes, from room temperature. T°C R-ohms T°C , R-ohms T°C R-ohms 45 10.5M 82 1380 137 45 47 lOiAM 84*5 noo 140 44 48.5 9100 87 1070 142 44 50 8850 89 990 144 44 52 8400 91 925 146 , 48 53.5 10.7M 93 800 148 39 95.5 625 157 36 97.5 525 159 36 99.5 455 161 36 101.5 420 163 36 103.5 385 165 34 105.5 355 167 33 108 315 169 ’ 33 no 275 171 32 113 190 173 33 n 6 130 176 36 n7 108 178 36 ns 102 180 36 120.5 58 182 36 123 57 184 36 125 55 186 36 127 51 188 36 129 51 190 36 131 49 192 36 135 48 (Continued on Next Page) ~53& >- T A B L E X III (Continued) 3BECXFIC RESISTANCES OF SODIUM STEA RA TE K 12.8# Water - 960 Cycles Third Rim Heated a'ppraximately 1° per 3 -4 .... minutes* s ta rtin g from room temperature T°C R-ohms T°C R-ohms 37 10. 6M : 95 430 39 9500 97 360 41 8800 99 320 43 8300 101 275 45 7850 103 260 47 7300 105 240 50 6650 107 250 53 6850 109 215 55 7050 111 190 57 7050 113 167 59 6950 115 148 61 6900 117 105 63 6600 119 84 65 6100 121 53 67 5700 123 48 69 4550 125 48 71 4000 127 48 73 3350 129 46 75 2750 131 45 77 2200 133 43 79 ' 1850 135 42 81 1270 137 42 S3 850 139 ’ 42 85 685 141 40 87 660 143 39 89 600 145 39 91 560 147 38 93 500 149 36 151 38 I O ~ ^‘ 5U ,p :yr,s,>y IM0‘ 5^0' /O' S * 10*' 2^Q°~ Ficj.YL 5 pe^ific of N*5*k A 0 .0 % Hz 0 9 6 0 G>cle^ C D F.rsi V'Jr^ Q 5 eC O < \ J r - i/ r\ • T L . • * ~ A •p. 1 0 *— 1 0 * 3 - Li 5 * ioa r s l C l_ < 0 2 * 1 0 ^ - 25 5 • ■ o t MO j,_ 5‘I0‘ a □ □ £78°-2f«^ j £ )• . . . . . . 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(^5 F t (i U . y u l v ( S o i n e t j l o i> /« f e d p o i .* v k $ O n\ I i i e . J (■ Otr O I' cld^ity i 2 l2 °- I 0 24-0-11 2 60°-1 2 160 /ftO 200 220 24-0 260 280 300 Te rv\ p e r d L u < Z ° C . 320 58 - 1*10* j* | 0 5 S'lO4 • 1 3 2 •- 1 4 -3 pc. C si t-i c o ; G t s . o O #* # • c < o o Q 0 F . y x . R e i I J t i i c<ri W j 5 i ( 2 .4 ^ HaO 9 6 0 Cycles F lrji r v r\ ^&coneJ ru ¥ \ a tu t rd ru r\ O F ° * r ir l\ *~u r\' • F . W k r o V \ EL (3 O W i l ' t t e J f t> V S e3 Uq o zianky | g * - < 3 pki * i g ) i * - v " £ . > 2 < IC T ; i*to4 Q C 1 5 M 0 3 « c u C O 2 * 1 0 * I* 10' 20 p K C triou5 oi » \'fe ; ia o - 1 6 Q a A a % \! A G J A ? 136'°- > 5 & a 2 0 4 - -17 264°- 1 8 5 -x lO * 2 *10 : ■ 1 0 * * 0 0 * 2 0 14-0 160 150 200 2 2 0 T e. ^ u^*i C. 24-0 260 270 300 - 5 9 - l* 1 0 ' S *IC T £1 * 1 0 _c O ( < u , ^5 * 1 0 ' cc -^ lo -3 x. C O 10 ' 2 “ I O '* 180°- 19 A A A So Q *d 202-20 F « g • XT Specific Re A 1 5 ce 5 of (V < 3 Sfv F " 2.5% Ha 0 4-20 Cycles Q Rirjt von Ccoofin'^) A .Second von © T~ U . i v J von (c o ol in g ) • Ro r i l\ V V V A - F HU. von ( So pooi ^ 5 o w\ i t t e d fov' 5 be o f 2 G O °->2 / ? 284-°-22 0 O G 6 MO*1 /2.0 1 4-0 160 180 ZOO 2 .2 0 * 4 0 ^ £60 2 & 0 3 0 O 3 2 O "T e nxpe v < 3 - ( we C. — O k ms c G Q G □ O P P m X) \ S' O \ '*'1 o - 4 / - IMG 5 * 10 ' : 10 * 5*I04 a > 2 . * I 0 <»M0 + a: »16-26 O o cfo i40- 2 a t? % F‘9 -K U L «3p*s-^i-f it. Re j i i t d M c e i of- N-a 5 4. I 4 . 4 - % H . O 9 6 0 C / cle^ FI r 5 4 VKJ IA . A S ec.o»\J /uvv a t w j r d a O F OSJ v V ~ K J • F , f i k vr / ( 5 owve 4 a l 4 | J i- ad jj O i n. i. s O iw i 4 4 . e J 4o*- »5cjJ«.e o 4 C t Sri ^ y In % r < * jp ^ ^ -j 5*I03 ■ 2, <n 20 \\rs> .^ & -H ev pyvvtovi r e d j i ki g. ■o \ 2 * I03 J* 10- 5* JO ' Dn 0 * D Qd % 163-29 3 A.Q •A Q • i 1 D x : A A A' A 1*10* I GO 120 14.0 I0O t6c 200 Te w > p»il^ci4rue'e °C. 220 240 2 60 2 6 0 300 C P o C o -N j ° G q B q , 0 G cP G □ Q 0 $ B tp i° C P A G □ (J) * T | * 5 0 U . s t * ~ -i 0_ ^ •< C C 3 L u \ < 5 ^ rv> ! f t 0 > ‘iS t « * t - UhrVvi - 63 - f > '9 - m i i © f I ! 2 . 3 % H a O 9 6 0 Cy^us 6 0 - 36 □O 6 5 °~ 3 7 100- 3fl II0 - 3 9 120-40 a_ ’ ° * ? * °P . O 192 ° - - - - - T o 36 Okms 60 ao 120 « . n - . -6&- g rap h s w ith many d i f f e r e n t s c a l e s , and i n some c a s e s , i n s e c tio n s * No f a r t h e r i n t e r p r e t a t i o n s o f any o f t h e d a ta w ere o b ta in e d from su c h p l o t s . In f u r t h e r d is c u s s i o n s , th e lo g a r ith m o f s p e c i f i c r e s i s t a n c e v s . te m p e ra t u r e p l o t s w i l l b e r e f e r r e d t o as "I*RTn c u r v e s . Each sam ple was s t u d i e d by a p ro c e d u re s i m i l a r to th e f o llo v /in g . An i n i t i a l ru n was made, and an LBT p l o t made. The l a t t e r o r d i n a r i l y i n d i c a t e d some s h a rp changes i n th e c u rv e * w hich w i l l be r e f e r r e d to a s " b r e a k s ." F u r th e r ru n s w ere made i n th e r e g io n o f th e s e b re a k s to a tte m p t to c o r r o b o r a te o r d isp ro v e th e m . O fte n o t h e r b re a k s o c c u rr e d , w hich w ere th e n ch ecked i n s u b s e q u e n t runs* Som etim es t h r e e o r f o u r ru n s w ere made to cheek e i t h e r a p a r t i c u l a r l y d o u b tf u l b r e a k o r one t h a t seem ed to have some s p e c i a l s i g n i f i c a n c e i n th e i n t e r p r e t a t i o n o f th e d a t a , a t l e a s t a t t h a t tim e . The d eg ree o f r e p r o d u c i b i l i t y i s shown c l e a r l y by th e d a t a , p a r t i c u l a r l y th e p l o t s . I t i s e v id e n t t h a t q u i t e o f t e n th e a b s o l u t e v a lu e o f t h e s p e c i f i c r e s i s t a n c e o f a g iv e n sam ple a t a g iv e n te m p e r a tu r e v a r i e s c o n s i d e r a b ly from ru n t o r u n , b u t t h a t i n g e n e r a l t h e la c k o f a b s o lu te r e p r o d u c i b i l i t y do es n o t a f f e c t th e te m p e r a tu re s a t w hich b r e a k s a p p e a r on th e LRT c u r v e s . Sam ples 0 and D ( F ig u r e s V II I and IS ) a r e exam ples o f t h i s b e h a v io r . The te m p e r a tu re s o f b r e a k s r a t h e r th a n th e a b s o l u te v a lu e s a r e u sed f o r m ost o f th e i n t e r p r e t a t i o n s in t h i s r e p o r t . - 6 5 - Some o f th e f a c t o r s w hich may have a f f e c t e d th e r e p r o d u c i b i l i t y o f th e a b s o lu te v a lu e s o f r e s i s t a n c e a r e la c k o f e l e c t r o d e c o n ta c t , c o r r o s io n o f th e e l e c t r o d e s , th e p re s e n c e o f s u b -m ic ro s c o p ic c ra c k s i n th e more s o l i d p h a s e s , and l a c k o f e q u ilib r iu m b e c a u s e o f to o r a p i d h e a t i n g or c o o li n g , p a r t i c u l a r l y i n th e l a t t e r b e c a u se of u n d e rc o o lin g . V i s u a l l y , a t l e a s t , th e r e was no e l e c t r o d e c o r r o s io n o f e i t h e r t h e t u n g s te n o r K ovar e l e c t r o d e s , a s judged by i n s p e c t i n g them a f t e r rem oving t h e sam p les from th e c e l l s su b se q u e n t t o a s e r i e s o f r u n s , and th e f a c t t h a t no d i s c o l o r a t i o n o f any sam ple was e v id e n t a t any tim e . The p o s s i b i l i t y t h a t s m a ll am ounts o f c o r r o s io n to o k p la c e c a n n o t be r u l e d o u t . As f o r e le c t r o d e c o n t a c t , i t was o b se rv e d t h a t u s u a l l y w e t ti n g o f th e e l e c t r o d e s to o k p la c e a t s u f f i c i e n t l y h ig h te m p e r a tu r e s ; a t lo w e r tem p era t u r e s , v a r y i n g w ith th e w a te r c o n t e n t , t h e o p a c ity o f th e sam ples made i t d i f f i c u l t t o d e t e c t th e p r e s e n c e o r a b se n c e o f c o n t a c t . O c c a s io n a l b u b b le s a t h ig h e r te m p e ra t u r e s w ere tro u b le s o m e , and a r e n o te d i n th e t a b l e s . • The r e p r o d u c i b i l i t y o f v a lu e s o f r e s i s t a n c e under v a r y in g c o n d it i o n s o f h e a t in g w ould seem to i n d i c a t e a t t a i n ment o f " e q u i l i b r i u m 1 1 , even th o u g h th e o n ly t r u e t e s t of e q u ilib r iu m i s th e a tta in m e n t o f th e same s t a t e upon e i t h e r h e a t i n g o r c o o li n g . P r e lim in a r y e x p e rim e n ts had i n d i c a t e d t h a t th e same b re a k s o c c u rre d . w ith r a t e s o f h e a tin g w hich v a r i e d w id e ly , a lth o u g h h e a tin g a t r a t e s f a s t e r th a n a b o u t 1° p e r 8 o r 3 m in u te s i n m ost te m p e ra tu re -.ra n g e s , r e s u l t e d i n b r e a k s w h ich occurred aiihigher te m p e r a tu r e s th a n w ith slo w e r h e a t i n g . The fo llo w in g d a ta show t h a t r e s u l t s "on th e r u n ” a p p ro a c h th o se o b ta in a b le a t c o n s ta n t tem pera t u r e . F o r Sample C (T able V I, F ig u r e V I I I ) m easurem ents ta k e n 15 m in u te s a p a r t a t 8 0 4 .5 ° and 804° gave 8300 and 8600 ohms f o r B, and m easurem ents 30 m in u te s a p a r t a t 836° gave 890 and 850 ohms f o r B . A m easurem ent on Sample F (T a b le s V I I I , F ig u r e IX) a t 1 3 6 °, gave a v a lu e f o r § t h a t f a l l s d i r e c t l y on t h e c o n t i n u a t i o n o f th e p r e v io u s ly o b ta in e d cu rv e w hose l a s t p o i n t was a t 1 3 8°, and was o b ta in e d 2 0 h o u rs p r e v i o u s ly ; th e sample had been k e p t in t h e oven d u rin g t h i s tim e a t a r e l a t i v e l y c o n s ta n t te m p e ra t u r e • For, c e r t a i n s a m p le s, and i n c e r t a i n r e g i o n s , f o r ex am p le, Sam ple F (T ab le IX , F ig u re X I ) , r e s i s t a n c e v a lu e s i d e n t i c a l w i t h i n e x p e r im e n ta l e r r o r w ere o b ta in e d even upon c o o li n g . In g e n e r a l , how ever, th e p o s s i b i l i t y o f u n d e rc o o lin g and t h a t o f th e s e p a r a t i o n o f th e soap from th e e l e c t r o d e s a s t h e soap c o n t r a c t s upon c o o lin g j u s t i f i e s t h e p ro c e d u re o f o b ta in in g d a ta a s th e sam ples a r e h e a te d . I t was f o r th e r e a s o n s above and i n o rd e r to g a th e r th e l a r g e am ount o f d a ta t h a t m ost o f th e ru n s w ere made a s t h e te m p e r a tu re in c r e a s e d a b o u t 1° p e r 3 - 4 m in u te s , and t h a t th e h i s t o r y o f each sam ple was r e c o r d e d f o r p o s s i b l e - 6 7 - f u r t h e r i n t e r p r e t a t i o n s i n th e f u t u r e . To sum m arize, a lth o u g h t h e s e d a ta have n o t "been p ro v e n c o n c l u s i v e l y to be e q u ilib r iu m o r t r u e c o n d u c ta n c e s a t a l l th e te m p e ra tu re s and c o m p o s itio n s i n q u e s t io n , th e b r e a k s i n th e I»BT c u rv e s a r e r e p r o d u c i b l e . Thus t h e s i g n i f i c a n c e of th e d a ta a t th e p r e s e n t tim e i s to be g a th e re d l a r g e l y from t h e b r e a k s , r a t h e r th a n t h e a b s o l u t e v a lu e s o f r e s i s t a n c e , i n th e c o u rs e s o f th e IBT c u r v e s . Such b r e a k s a r e m arked b y number on each o f th e F ig u r e s VI to XV, and shown i n c l a s s i f i e d form i n T able XXV. A l l p o i n t s o f d o u b tf u l v a l i d i t y a r e l a b e l l e d w i t h a q u e s tio n m ark (?). P o i n t s n o t so m arked w ere e s t a b l i s h e d by a minimum o f tw o, and in many c a s e s t h r e e o r f o u r s e t s o f o b s e r v a t i o n s . 3 . P hase I m p lic a tio n s I t i s r e a s o n a b le to p o s t u l a t e t h a t a b re a k i n th e IBT c u rv e c o rre s p o n d s to a change i n p h a s e , a s shown in C h a p te r I I I f o r a n h y d ro u s sodium p a l m i t a t e . T h is i s s u b s t a n t i a t e d b y th e f a c t t h a t a n h y d ro u s sodium s t e a r a t e (F ig u re VI) shews a b r e a k i n i t s LBT c u rv e a t 2 5 5 °, a v a lu e d i f f e r i n g b y l e s s th a n th e p ro b a b le e x p e rim e n ta l e r r o r from 2 5 7 °, a t w hich te m p e r a tu r e th e change from th e s u b n e a t to n e a t p h a se i s w e ll- e s ta b lis h e d by d i l a t o m e t r i c 23 and h o t- w ir e m eth o d s. A ll of th e p o i n t s above 100° i n T able XIV w ere ^ 8 - TABLE XIV C O ID U C T IM E T R IC C H A N G E S O C C U R R IN G IN SO D IU M S T E A R A T E SY ST E M S O F L O W W A T E R C O N T E N T (The Numbers Refer to P oints on the L R T Curves o f Figures VI to XV) Composition of Sample and Frequency of Measurement of Change Slope of LRT Curve Sample A Sample B . Sample C 0 .0 # 0,5/S 1,0?S Water Water Water 960 Cycles .420 Cycles 960 Cycles Sample D Sample E Sample F 2,0^ 2,47S 2 , 57s Water Water W ater* 960 Cycles 960 Cycles 420 Cycles Sample H Sample I Sample J 3»37£ 4,4?5 .6*575 Water Water Water 960 Cyeles 960 Cycles 960 Cyoles Sample K 12.875 Water 960 Cycles Id en ti fic a tio n or> F ig, XVI. Most marked change - 265° 246° ’ 224° 2120 .204° 2020 187° 1880 i'160° - 1700) 1200 Change in L R T Curve ■ from large slope to I ■ alm ost f la t 2 3 7 10 17 20 25? 29 33 - 34 •-/ 40 Changes occurring a t 278° 275° ' 268° 2 4 0 °-ll? 264o ^ § 2600-21? temperatures higher 2600-12? 0 than the most marked 2(a) 4? 8 2860-137 284°-22 change above In fle c tio n of L R T 249° 180° 1849 180° 180° 1400 curve previous to most ▲ marked change above 17 6 9 16 ’ 19? 28? .Discontinuous changes 132°-14 1300-23 1160-26 500-35 or apparent anomolies 120°-26(a) CD such as increases of 1240-27 1200-31 60°-36 slope or M f la t s ” 13fe°-l5? 1340-24 Other changes 160° 128°-327 85°-37 e 1000-38 5 1000-30 11QO-39 L iterature Values References: 23, 24, 2 E, 26, • fit O I 6C © poq K C D l tjpocj Xx&p^- CC 5 rp *N vr*g oaf - n e>' ^ s Jfo 'w w p jt H e i Q -fc9- p l o t t e d on a co m p o sitio n - te m p e ra tu re diagram , F ig u re XVI. _ P o i n t s from l i t e r a t u r e so u rc e s were l ik e w is e in c o r p o r a te d . The le g e n d s f o r b o th s e t s of th e s e v a lu e s a r e shown in th e T a b le . When t h i s was done,, i t was found p o s s i b l e . t o e s t a b l i s h d e f i n i t e l y c e r t a i n phase b o u n d a rie s and i n d i c a t e a t l e a s t t h e b e g in n in g d i r e c t i o n s f o r o t h e r s . A d e t a i l e d d is c u s s io n f o l l o w s : P o in ts 6, 9, 16, 19, 25 (?) and 29 d e f i n i t e l y e s t a b l i s h a e u t e c t o i d , a lth o u g h 29 may be a p o in t on th e l e f t - h a n d boundary o f soap b o i l e r ' s n e a t so a p . The lower c om po sition of superwaxy soap in e q u ilib r iu m w ith su b n e a t soap a t t h e e u te c t o i d i s f a i r l y w e ll f i x e d by th e l i t e r a t u r e and th e p r e s e n t e x p e rim e n ta l p o i n ts shown, a lth o u g h th e y a r e r a t h e r s c a t t e r e d . I t i s u n f o rtu n a te t h a t r e s i s t a n c e v a lu e s of sample. B (0 .5 $ w a ter) were too high to m easure below 200°. The ch an ges i n d i c a t e d by 6, 9, 16, and 19 were of a d i f f e r e n t typ e from th o se of 25 (?) and 29; a s can be se en from T able XlY and the Graphs* th e form er marked th e o n s e t o f a phase w ith a v a ry l a r g e n e g a tiv e t e m p e r a t u r e - c o e f f i c i e n t o f r e s i s t a n c e , w hereas the l a t t e r group marked th e b e g in n in g s of th e d isa p p e a ra n c e of such a p h a se . T his s e r i e s < o f o b s e rv a tio n s e s t a b l i s h e s the c o m p o sitio n of t h i s phase a t th e e u te c t o i d as betw een 2 .5 and 3 .3 $ . P o in t 2, w hich checks th e l i t e r a t u r e v a lu e f o r the anhydrous su b n e a t to n e a t soap t r a n s i t i o n , and p o in ts - 7 1 - 3 , 7, 10, 17, and 20 a re tafeen a s th e upper rig h t- h a n d boundary o f th e su b n e at f i e l d . At th e s e p o i n t s th e LET c u rv e s change from v e ry la r g e n e g a tiv e s lo p e s to s lo p e s t h a t a r e alm ost f l a t . When th e l i n e c o n n e c tin g th e p o i n t s above i s ex tend ed toward p o in t 25 ( ? ) 9 i t becomes e v id e n t t h a t t h e co m p o sitio n a t th e end o f th e ’’tongue" i s v e ry c lo s e to 3 .3 $ , and t h a t t h e "tongue" p h a se i s su b n eat so a p . When a sample i s h e a te d th ro ugh a te m p e ra tu re which ta k e s i t p a s t the r ig h t- h a n d boundary of th e su bneat f i e l d * t h e su b n e a t phase b e g in s to d is a p p e a r w ith the sim u lta n eo u s fo rm atio n o f a new p h a se , to b e s p e c i f i e d s h o r t l y . A lthough th e te m p e ra tu re a t w hich t h i s change occu rs d e c r e a s e s w ith i n c r e a s i n g w a te r c o n t e n t , th e v a lu e s o f th e s p e c i f i c r e s i s t a n c e s a t th e s e te m p e ra tu re s go th ro u g h a minimum, fo llo w ed b y a f u r t h e r d e c re a s e , as shown b e lo w . C om position, § - ohms T°C $ Water __________ ___________ 0 .0 640 255° 0 .5 40Q 246° 1 .0 600 224° 2 .0 300 212° 2 .5 220 204° T h is s e t of o b s e r v a tio n s was ta k e n a s p resum ptive ev id en ce t h a t th e p hase formed upon h e a tin g a 0 .0 $ w a te r sample was d i f f e r e n t from th e one formed upon h e a tin g a 1 .0 $ sam ple. Since t h e phase r u l e r e q u i r e s a e u t e c t o i d f l a t between su b n e a t and s u p e m e a t so a p , and th e o nly o th e r p o in t to - 7 2 - c o r r e l a t e w ith t h i s evid en ce i s 11 ( ? ) , the f l a t i s drawn a t 240°, a lth o u g h the te m p e ra tu re i s n o t a t a l l c l o s e l y d e fin e d . T he-upper r i g h t- h a n d boundary of th e n e a t f i e l d i s e s t a b l i s h e d by p o i n t s 4 , 8, and 12, and c o n tin u e d to the 0 m e u t e c t o i d a t 240 . The i n t e r s e c t i o n of t h i s boundary w ith the e u t e c t o i d , when c o n n ected to th e p o in t of th e su b n eat - n e a t tra n s fo rm a tio n on th e anhydrous axis* e s t a b l i s h e s ro u g h ly the low er r ig h t boundary of th e n e a t f i e l d . In t h i s c o n n e c tio n i t i s of i n t e r e s t to n o te t h a t th e lower r ig h t- h a n d boundary of th e subneat f i e l d d id n o t appear from th e conductance data e i t h e r . Uo e x p la n a tio n f o r t h i s i s a p p a re n t to th e w r i t e r . In th e l a t t e r c a s e th e r e a re 24 some s c a t t e r e d c a l o r im e tr i c d a ta which se rv e t o i n d i c a t e th e p ro b a b le p o s i t i o n of th e boundary. P o i n t s 13 f?) and 22 seem to f a l l on th e w e l l - e s-ta b lis h e d low er boundary of th e f i e l d o f i s o t r o p i c s o l u t i o n . A e u t e c t o i d f l a t j u s t above 260° was i n d i c a t e d by p o in ts 12 ( ? ) , 18, arcd 2 1 , i n good agreem ent w ith th e v a lu e o f 262° found b y J . W. McBain, B. P. Y old, and 25 M. F r ic k from a minimum i n th e T ^, c u rv e . The above r e s u l t s r a t h e r d e f i n i t e l y e s t a b l i s h t h a t p a r t of th e phase r u l e diagram of th e sodium s t e a r a t e - w a ter system from 170° to 300°, and below about 5fo w a te r . A lthough th e "tongue" type o f c o n s t r u c t i o n has long been su g g e ste d in t h i s re g io n f o r v a rio u s so a p s, and even r e a s o n a b ly w e l l - e s t a b l i s h e d f o r sodium m y r is ta t e by - 7 3 - v i s a a l and m ic ro sc o p ic methods, t h e r e i s no p h a s e - r a le diagram in th e l i t e r a t u r e f o r th e sodium s t e a r a t e - w a t e r system i n t h i s r e g io n h a s e d on e x p e rim e n ta l p o i n ts o th e r th an th e w e l l - 23 e s t a b l i s h e d anhydrous tra n s fo r m a tio n s * J . W. McBain and 27 W. W. Lee* on no s t a t e d o r d i s c e r n i b l e e v id e n c e , have gone as f a r as to draw t h e sub n e a t and n e a t nto n g u e sn in to th e com position of about 10fo w ater* T his presum ption i s n ot i n a c c o rd w ith th e p r e s e n t e x p e rim e n ta l ev id en ce, w hich proves them to ex ten d in to about: 4$ and 3$, r e s p e c t i v e l y . 24 O a lo rim e tric d a ta o b ta in e d by B. P. Void a ls o app ear to i n d i c a t e t h i s s m a ll e r ra n g e o f e x is te n c e of th e sub n eat and n e a t phases# A lthough th e te m p e ra tu re of p o i n t s 33 and 34 fo r sample J (6#5$ w a te r) i s n ot to o w e l l- d e f in e d , th e c h a r a c t e r i s t i c s o f th e c o rre sp o n d in g change a r e s i m i l a r to th o se of p o in t 40 fo r sample K (12*8$ w a te r)* ^he l a t t e r f a l l s , on th e p r e v i o u s ly - d e f in e d Tc c u rv e , and so t h a t curve i s t e n t a t i v e l y c o n tin u e d th ro u g h p o i n ts 33 and 34. The b r a c k e te d and p o o r ly - d e f in e d p o in ts a t 168° and 183° 25 (9*5fo w a ter)* a re b a se d on m icro sco p ic o b s e r v a tio n s . Thus th b t o t a l ev id ence does n o t exclud e the, p o s s i b i l i t y t h a t p o i n t s 33 and 34 m ight be on th e soap b o i l e r ' s n e a t soap-waxy soap e u t e c t o i d , and t h a t c o rre s p o n d in g ly , Tq c o n tin u e s alm ost v e r t i c a l l y from 128° and 9 .5 $ .w a te r c o m p o sitio n . - 7 4 - The upper r i g h t boundary of the superwaxy f i e l d i s c o n tin u e d helow th e e u te c t o i d f l a t a t 1 80°, and in a c c o rd w ith th e p h a se r u l e , t h e low er boundary of t h a t f i e l d i s drawn from th e anhydrous a x i s a t t h e waxy-superwaxy t r a n s i t i o n to th e soap b o i l e r ' s n e a t soap-waxy soap e u te c to id * The p o s i t i o n o f t h i s e u te c t o i d i s i n d i c a t e d , a lth o u g h i t s te m p e ra tu re i s v e ry p o o r ly defined * The j u s t i f i c a t i o n f o r draw ing t h e " f l a t ” a t abou t 160° i s th e t e n t a t i v e p o s i t i o n o f th e upper r i g h t boundary of th e waxy f i e l d , as d is c u s s e d in t h e n e x t p a ra g ra p h , t o g e t h e r w i t h the n e c e s s i t y t h a t the t r i p l e p o in t must be on t h e e x te n s io n of th e upper r i g h t boundary o f th e superwaxy f i e l d , and th e presump t i o n t h a t the lower boundary of th e superwaxy f i e l d s lo p e s downward* The l a r g e v a lu e s of r e s i s t a n c e s made measurements im p o ssib le in th e re g io n o f t h e subwaxy-waxy t r a n s f o r m a ti o n , (about 13£° f o r th e anhydrous s o a p ) , a t w a te r c o n e e n tr a tio n s o f Zfo o r le s s* The c o n stan cy of th e te m p e ra tu re of t h i s tr a n s f o r m a tio n a s th e w a te r c o n te n t i s in c r e a s e d from 0*0 o/ to 1 .9 $ , as judged by c a l o r i m e t r i c d a ta , l e d S . D# Void to p o s t u l a t e a c o n s t r u c t i o n of th e ty p e shown in th e lower l e f t c o m e r of f i g u r e XVI. The p r e s e n t d a ta a r e in a c c o rd w ith t h i s p o s t u l a t e . P o in ts 26 and 31 c o u ld waLX b e on t h e soap b o i l e r ' s n e a t soap-waxy soap e u t e c t o i d . The v e ry s i n g u l a r b e h a v io r of sample I (4 .4 $ w a te r) as shown in f i g u r e X I I I , nam ely, a d e c re a se o f B o f alm ost 10 f o l d as - 7 5 - th e te m p e ra tu re i s in c re a s e d from 116° to 120°, fo llo w ed by a f l a t in t h e LRT c u rv e t o 124°, can be i n t e r p r e t e d a s meaning a s e r i e s o f changes n e a r a t r i p l e p o in t on a phase diagram (p o in ts 26, 26a and 27)* She p a i r s of p o i n t s 14 and 15 ( ? ) , an d 23 and 24r r e p r e s e n t f l a t s or "p ea k s” on t h e LRT c u rv e s , a lth o u g h th e form er f l a t i s of d o u b tfu l v a l i d i t y . A p o s s ib le i n t e r p r e t s t i o n of th e s e p a i r s o f p o i n t s is t h a t , as th e te m p e ra tu re i s in c r e a s e d , sam ples P and H (2 .5 and 3 .3 $ w a te r r e s p e c t i v e l y ) , a s shown in F ig u re s XI and X I I , p a ss th ro u g h a narrow two phase r e g io n , presum ably subwaxy and waxy so a p , w ith lth e form er having a low er sp e cific- r e s i s t a n c e . The d o tte d b o u n d a rie s shown in th e above r e g io n — from a b o u t 0 to 6$ w a te r and from a b o u t 110° to 140°C— a re p r e s e n te d i n accordance w ith th e f a c t s and i n t e r p r e t a t i o n s j u s t g iv e n . However, a n o th e r s e r i e s of b o u n d a rie s has pw been su g g e s te d . J . W. McBain and W. W. Lee , on th e b a s is o f vapor p r e s s u r e e v id e n ce , show th e waxy "tongue" e x te n d in g down to 15$ w a te r and 100°0, i n d isagreem en t w ith th e p r e s e n t resu lts* . They have no e x p e rim e n ta l r e s u l t s on t h i s tongue a t c o m p o sitio n s of l e s s th an 8$ w ater* O bviously more work is needed in t h i s r e g io n to c l a r i f y th e phase p i c t u r e . ' - 7 6 - 4 , Frequency Dependence of C o n d u c tiv ity A few measurements were made to determ ine w hether or n o t the c o n d u c t i v i t i e s o b ta in e d were frequency-dependent* A l i s t i n g of fre q u e n c ie s* te m p e r a tu r e s , s p e c i f i c r e s i s t a n c e s , and co m p o sitio n s o f sam ples i s g iv e n in Table &V. P re v io u s to a s e r i e s o f measurements,, t h e sam ples had b e en heated or co o le d v e r y r a p i d l y (10-20° p e r m inute) to th e tem pera t u r e in q u e s tio n * and th e n th e hea t i n g o f the oven was a d ju s te d so t h a t th e te m p e ra tu re rem ained s u b s t a n t i a l l y c o n s ta n t d u rin g a l l the m easurements a t t h a t te m p e ra tu re . Measurements on any p a r t i c u l a r sample w ere made a t i n c r e a s i n g f r e q u e n c i e s , and th e n th e r e s i s t a n c e a t th e lo w est freq u e n cy was re-m e a su re d to p re c lu d e th e p o s s i b i l i t y of a d r i f t . I t i s a p p a re n t t h a t , w i t h i n e x p erim e n tal e r r o r , th e r e i s no v a r i a t i o n of c o n d u c tiv ity w ith fre q u e n c y a t th e te m p e ra tu re s an d c o m p o sitio n s t a b u l a t e d . The r e s u l t s w i l l be d is c u s s e d in th e c o n c lu d in g s e c t i o n in t h i s ch ap ter* - 7 7 - TABUS X V FREQUENCY DEPENDANCE OF CONDUCTIVITY OF SODIUM STEARATE - WATER SAMPLES Composition - Specific Frequency- Temperature °C % Water Resistance - ohms cycles 168.5 2.0 14>000 420 168.5 2.0 13,800 3,500 168*5 2.0 13,500 7,800 168.5 168.5 168.5 214*0 214*0 214*0 2.5 2.5 2.5 2.0 2.0 2.0 214.0 214*0 214.0 2.5 2.5 2.5 >.5 240.5 0.5 0.5 2.050 2,100 2.050 325 325 325 420 3,500 7,800 3,500 7,800 255 250 420! 3,500 7,800 78,000 78,000 3,500 300.0 300.0 300.0 0.5 0.5 0.5 310 315 315 420 3,500 7,800 - 7 8 - b. I n t e r p r e t a t i o n s o f t h e C o n d u c t i v i t i e s The movement of charged p a r t i c l e s i n an e l e c t r i c a l f i e l d c o n s t i t u t e s c o n d u c t i v i t y . In a f i e l d which does not change d i r e c t i o n w ith tim e, th e p a r t i c l e s t h a t move may be e le c tro n s,, io n s , or b o th . In an a l t e r n a t i n g f i e l d , i t i s a lso p o s s i b l e f o r any d ip o le s p r e s e n t to r o t a t e w ith the f i e l d , w ith th e r e s u l t t h a t a d d i t i o n a l e l e c t r i c a l conductance o c c u rs . The l a t t e r may be determ ined e x p e rim e n ta lly f o r any f r e q u e n c y by s u b t r a c t i n g th e d i r e c t - c u r r e n t conductance from th e t o t a l a l t e r n a t i n g - c u r r e n t c o n d u ctan ce. The e l e c t r i c a l c u rre n t s e t up as th e d ip o le s fo llo w th e a p p lie d v o lta g e i s in phase w ith i t , and i s r e f e r r e d to as " c a p a c ity " c u r r e n t . i t v ery h ig h f re q u e n c ie s the d ip o le s a r e in c a p a b le of fo llo w in g th e f i e l d ; a t v e ry low fre q u e n c ie s , t h e f i e l d does not change d i r e c t i o n o fte n enough p e r u n i t of time to r e s u l t i n l a r g e c a p a c i ty c u r r e n t s . Q u a n t i t a t i v e l y , i t is p o s s ib le to s e t up th e s e r e l a t e d e q u a tio n s : . C H tLsn < p = ^ where (1) i s th e l o s s a n g le , £ " is a l o s s f a c t o r ?/hich can be c a l c u l a t e d a s shown below , and £ 1 is th e o rd in a ry d i e l e c t r i c c o n s t a n t , a l l a t a given freq u e n cy ; and / * * ........................................ *The d i s c u s s i o n of d ip o la r r o t a t i o n t h a t fo llo w s i s based on th e survey a r t i c l e of r e f e r e n c e 27. - 7 9 - C /;_ ^ t o t a l A.C. conductance ^ 18 x 1 0 I T , (2) ^ t o t a l D*C. c o n d u c ta n c e / f where f 'i s th e fr e q u e n c y * f ^ g o e s through a maximum w ith fre q u e n c y , as d is c u s s e d above. That no a p p re c ia b le p a r t of th e conductances r e p o r t e d i n t h i s d i s s e r t a t i o n c a n he due to d ip o le r o t a t i o n i s shown by th e fo llo w in g d i s c u s s i o n . A lthough i t was d i f f i c u l t to o b t a i n c o n s i s t e n t measurements of r e s i s t a n c e on a d i r e c t c u r r e n t b r id g e fpresum ably b e ca u se of p o l a r i s a t i o n ) , a few e x p lo r a to r y measurements made seemed to i n d i c a t e b u t l i t t l e d i f f e r e n c e betw een th e a l t e r n a t i n g and d i r e c t - c u r r e n t r e s i s t a n c e s fo r a given sample a t th e same te m p e ra tu re . Furtherm ore,, v a lu e s o b ta in e d fo r a l t e r n a t i n g - c u r r e n t conductances due to dipole r o t a t i o n a re g e n e r a l l y of th e -10 -6 o rd e r o f 10 ohms; th e c o n t r i b u t i o n of t h i s to 10 ohms, th e h ig h e s t value m easurable w ith th e b rid g e used, i s n e g l i g i b l e . F i n a l l y , r e s i s t a n c e s d id n o t v a r y w ith f r e q u e n c ie s in the ran g e of 420-7800 c y c le s in a t l e a s t . th e te m p e ra tu re and co m p o sitio n r e g io n s shown in Table XV. P o s s ib le f l a t s ,in th e ^-frequency cu rv e s over t h i s ran g e o f over f o u r o c tav es c an n o t be r u l e d o u t, b u t seem q u ite u n l i k e l y . E le c t r o n conductance has been observed f o r a c l a s s 3 0 of s u b s ta n c e s known a s se m i-c o n d u c to rs. These a re b i n a r y compounds, and the amount o f conductance i s v e ry s e n s i t i v e to th e gas p r e s s u r e of th e f r e e io n ic c o n s t i t u e n t . - 8 0 - Aside from m e ta ls , th e r e a re no o th e r m a t e r i a ls which r e p o r t e d l y show e l e c t r o n co nd uctance. The fo re g o in g d i s c u s s i o n le a d s to t h e c o n c lu sio n t h a t th e observed c o n d u c t i v i t i e s must be due to io n ic m ig ra tio n * The known,m i c e l l a r s t r u c t u r e of the sodium- s t e a r a t e system s s t u d i e d in t h i s r e p o r t * , t o g e t h e r w ith the s i z e and shape of th e s t e a r a t e ion as compared w ith the sodium io n , makes i t r e a s o n a b le to s t a t e t h a t th e l a t t e r i s the c o n d u c tin g s p e c ie s alm ost e x c l u s i v e l y . T ra n s fe re n c e exp erim ents would be n e c e s s a ry to c o rr o b o r a te th e p o i n t • A ccepting t h a t th e mechanism of conductance i s a movement of sodium i o n s , one may s p e c u la te a s to th e i n t e r m ediate or a c t i v a t e d p o s i t i o n s o f th e s e i o n s . There a re fo u r ty p e s of in te r m e d i a t e p o s i t io n s f o r the sodium ions as th ey move out of t h e i r p o s i t i o n s in th e m ic e l l e s , namely (1) v a c a n t d e f e c t s i n th e l a t t i c e , commonly c a l l e d " h o l e s " , (2) i n t e r s t i t i a l p o s i t i o n s in t h e p o l a r p a r t o f th e l a t t i c e , (3) i n t e r s t i t i a l p o s i t i o n s in th e non-po-lar p a r t of the l a t t i c e , and (4) p o s i t i o n s in th e ^p-aces between m i c e l l e s . S ince conductance i s a d i f f u s i o n p r o c e s s ,* * i t is p o s s ib le to e v a lu a te th e c o n s t a n t s i n the a p p li c a b l e d i f f u s i o n f equ ation* and to a tte m p t to make a d e c is io n among the fo u r a c t i v a t e d s t a t e s above from the c o n s ta n ts o b ta in e d . *Summarized by T, Doscher in r e f e r e n c e . 7. **The g e n e ra l d is c u s s io n o f th e n e x t few pages i s b a sed on r e f e r e n c e 3 /. “ 8 1 " When one io n i s th e c o n d u c tin g sp ecies,, th e v a l i d i t y of the law , - I - K - A n RT (3) (where K i s t h e s p e c i f i c con d u ctan ce, A and E a re c o n s ta n ts , and B and T have t h e i r u su a l s i g n i f i c a n c e ), has heen w e ll e s t a b l i s h e d . The sm all tem p era tu re range of e x is te n c e o f each of the phases i n th e p re s e n t stu d y makes i t d i f f i c u l t to c o n c lu s iv e ly prove t h a t t h i s law o b ta in s i n th e s e sy ste m s, a lth o u g h th e argum ent above i n d i c a t e s t h a t i t d o e s. Many q u a n t i t a t i v e i n t e r p r e t a t i o n s have been p la c e d upon A and E, bu t i t is d e s i r a b l e to emphasize t h a t q u a l i t a t i v e l y (1} A i s a freq uency f a c t o r , connected w ith th e p r o b a b i l i t y of a d i f f u s i o n or t h a t o f an io n becoming a e endue t o r , and (2) E i s th e energy b a r r i e r , t h a t an io n must surmount to get i n t o th e t r a n s i t i o n s t a t e . E v a lu a tio n o f th e c o n s ta n ts i n e q u a tio n (3) has been c a r r i e d out in th e r e g io n of th e s u b -n e a t to n e a t soap t r a n s i t i o n . I t w i l l be r e c a l l e d t h a t a t th e p o in ts which have been i n t e r p r e t e d as t h a t o f th e t r a n s i t i o n s ju s t m entioned, th e LBT cu rv es showed sh a rp b r e a k s , changing, t h e i r slo p e s from la r g e n e g a tiv e v a lu e s to th o s e t h a t a re alm ost f l a t . The c o n s t a n t s were e v a lu a te d ' by ch o o sin g two p o in ts each i n the s u b - n e a t and n e a t soap r e g i o n s from t h e b e s t smooth LBT c u r v e s . The p o in ts w ere ch osen as c lo s e to th e t r a n s i t i o n s as p o s s i b l e , and th e c o n s ta n ts e v a lu a te d from sim ultan eo us s o l u t io n s of e q u a tio n (5) f o r each r e g io n ! The r e s u l t s a re shown below . % : ^ a ^ e r Content Subneat Begi on Heat Begion A* E* A* E* 2 .5 x 10 2 104 3 x 103 <10 4 .6 x 10 4 6 x 10 4 4 x 10 2-4 x 10 5 1 x 10 ( D i f f i c u l t to h a v io r of c u rv e s , b u t in every c a s e , th e same typ es of v a lu e s as f o r th e c a l c u l a t e becau se of e r r a t i c b e - * - 1 -1 A i s in ohm cm . *E i s in c a l o r i e s / m o l . 0 .5 $ w a te r sa m p le .) The v a lu e s f o r A i n th e su b n e at reg io n a re c o m p le te ly d i f f e r e n t from v a lu e s re c o rd e d in th e l i t e r a t u r e f o r s a l t s below t h e i r m e ltin g p o i n t s . The ran g e fo r th e l a t t e r i s 6 o f t h e o rd e r 10 < A <10 . Whether A i s i n t e r p r e t e d ¥c c l a s s i c a l l y or by th e th e o ry of Eyring* th e v a lu e s of A i n th e subneat r e g io n can mean o nly one th in g - t h a t th e p r o b a b i l i t y of g e t t i n g in to th e t r a n s i t i o n s t a t e i s v ery s m a ll. The l a t t e r th e o ry im p lie s t h a t th e re i s a b ig e n tro p y in c r e a s e i n p a s s in g in to th e a c t i v a t e d s t a te * or a l a r g e d is tu r b a n c e f t h a t is* a b i g d is o r d e r ) in the l a t t i c e i n t h a t s t a t e . Of th e f o u r t r a n s i t i o n r e g io n s in to which th e sodium ion s may be f o rc e d i n an e l e c t r i c f i e l d , i t i s *B eference 3/ , Page 302 - 8 3 - th u s p o s s ib l e to r a l e o a t th o se of f l ) " h o le s ” in the l a t t i c e , and (2) i n t e r s t i t i a l p o s i t i o n s in th e p o l a r p a rt of th e l a t t i c e . These two a r e th e o n ly p o s s ib le in te r m e d ia te p o s i t i o n s i n o r d in a ry ionic, c r y s t a l s , and as shown above, th e v a lu e s of A o b ta in e d f o r th e su b n eat re g io n a re of an e n t i r e l y d i f f e r e n t o r d e r of m agnitude from th o se f o r io n ic c r y s t a l s . Of th e two. rem ainin g t r a n s i t i o n r e g io n s , i t seems much more re a s o n a b le f o r sodium io n s to jump from m ic e lle to m ic e lle th ro u g h sp a c e s between them th an i t does t o p i c t u r e t h e i r jumping from one p o la r re g io n to a n o th e r through th e space between hydrocarbon t a i l s . C e r ta in l y th e v a lu e s of A f o r e i t h e r of th e two l a t t e r a c t i v a t e d s t a t e s sho uld be e x trem ely h ig h . The f i r s t few p e rc e n t o f w a te r added to sodium s t e a r a t e i s undoubtedly o r ie n te d a t t h e p o la r h e ad s. T his r e s u l t s i n a lo w e rin g o f th e d i e l e c t r i c c o n s t a n t . Dr. Sidney Benson has su g g ested t h a t th e s im p le s t e x p la n a tio n f o r th e d e c re a s e of E w ith i n c r e a s in g w a te r c o n te n t i s t h i s lo w e rin g o f th e d i e l e c t r i c c o n s t a n t . S in c e , a c c o rd in g to. E y r in g 's * t h e o r y f E i s r e l a t e d l o g a r i t h m i c a l l y to A, th e d e c re a se of E w ith in c r e a s in g w a te r c o n te n t i s lik e w is e e x p la in a b l e . At th e subneat to n e a t soap t r a n s i t i o n , the d i p o la r bonds s t a r t to b r e a k , a llo w in g much more m otion o f the n o n -p o la r t a i l s , p r e v io u s ly c o n s tr a in e d by o r i e n t a t i o n of the p o la r heads. Here i t would seem *K eference 31 , page 302. - 8 4 - p o s s ib le f o r th e t a i l s to do some of th e condacting# Where the d ip o la r bonds have b ro k en , the degree o f m o b ility of th e io n s sh oald be s i m i l a r to t h a t i n a l i q u i d , d e s p i te th e f a c t th a t o th e r ev id e n ce shows 7 th e p e r s i s t e n c e of sm e ctic p la n e s in th e n e a t phase# The e x p e c te d drops i n A and E o ccu r a t th e t r a n s i t i o n . The r e s u l t s on anhydrous sodium p a lm i ta te a r e q u ite s i m i l a r q u a l i t a t i v e l y . I t would seem t h a t f u r t h e r experim ents com paring the conduetim e t r i e b e h a v io r of o th e r pure soaps w ith th e s e two m ight le a d to a f u r t h e r i n s i g h t i n to th e f a c t o r s which a f f e c t th e v a rio u s l i q u i d - c r y s t a l l i n e p r o p e r t i e s of soaps# The c o m p lex ity of th e LBT c u rv e s i n b th e r re g io n s makes a n a ly s e s of th e type above' u n f e a s ib le a t p re s e n t# More ad eq u ate c o n t r o l of some of th e f a c t o r s which a f f e c t th e a b s o lu te v a lu e s of r e s i s t a n c e s , d is c u s s e d on pages 65-67, would be n e c e s s a ry to j u s t i f y such an aly se s# D i e l e c t r i c m easurements a re also in d ic a t e d fo r f u r t h e r stu d y i n th e re g io n s of low er te m p e ra tu re and w a te r c o n te n t. - 8 6 - 2* I E Blunge? C e ll An a tte m p t was made to stu d y c o n c e n tra te d sodium s t e a r a t e - w a t e r system s a t low er te m p e ra tu re s th an th o s e which were found c ap a b le o f b e in g s tu d ie d by employing th e , " p a r a l l e l - w i r e " c e l l s d e s c rib e d i n s e c t i o n A o f t h i s c h a p t e r . A v e ry l a r g e number o f experim ents w ere c a r r i e d out in th e hope o f making th e p lu n g er c e l l (d e s c rib e d i n Chapter I I ) y i e l d c o n d u c tim e tric measurements t h a t were r e p r o d u c ib le , a t l e a s t as to " b re a k s1 1 in t h e "LBT" c u rv e s , i f n o t in a b s o lu te v a l u e s • Two o f th e v e ry s e r io u s d i f f i c u l t i e s en co u n tere d were (1) th e l a c k of a tta in m e n t of c o n s ta n t v a lu e s f o r th e r e s i s t a n c e s o f sam ples as the p r e s s u r e s on them were v a r i e d a t giv en te m p e ra tu re s , and, r e l a t e d to t h i s d i f f i c u l t y , (£)_ changes in g r o s s c o m p o sitio n s of samples d u rin g th e c o u rse o f p re s s u re ’’t r e a t m e n t ," as w e ll ,as d u rin g h e a t in g . I t was' soon found t h a t i n c r e a s in g th e p r e s s u r e s on sodium s t e a r a t e sam ples o f low w a te r c o n te n t low ered th e m easured r e s i s t a n c e s * Because o f th e h a rd , crum bly n a tu r e o f th e s e system s, t h i s was a t f i r s t i n t e r p r e t e d as meaning a l a c k o f e le c tr o d e c o n t a c t , and th u s many a tte m p ts were made t o s e c u re c o n s t a n t r e s i s t a n c e re a d in g s by i n c r e a s in g th e p r e s s u r e s . That th e la c k of e le c t r o d e c o n ta c t was to o sim ple an e x p la n a tio n f o r th e b e h a v io r n o te d i s proven by th e f a c t t h a t a t some p r e s s u r e o f a few th ousand pounds or - 8 7 - s o , depending on th e sam ple, th e r e s i s t a n c e in c r e a s e d w ith th e p r e s s u r e , and a t some h ig h e r p r e s s u r e , the f i r s t n o te d d e c re a se of r e s i s t a n c e w ith p r e s s u r e ag ain came i n t o th e p i c t u r e . A lso, i f th e p r e s s u r e was a llo w e d t o rem ain a t c e r t a i n v a lu e s , th e r e s i s t a n c e v a lu e o f a sa m p le .in c re a s e d w ith tim e, w hereas th e re v e r s e was t r u e a t o th e r p r e s s u r e s . S t i l l f u r t h e r , when th e p re s su re , was r e l e a s e d from a system and th en r e - a p p l i e d up to t h e p rev io u s v a lu e , r e s i s t a n c e v a lu e s were m arkedly low ered, and d id n o t always d r i f t toward th e o r i g i n a l re a d in g o f r e s i s t a n c e a t t h a t p r e s s u r e . To Complicate: t h e ..p i c t d r e f d r t h e r , i t was im p o ssib le to m a in ta in p r e s s u r e s over any g r e a t le n g th of tim e , The C arver P r e s s used did m a in ta in re a s o n a b ly c o n s t a n t p r e s s u r e s on m e t a l l i c o b j e c t s over lo n g p e rio d s of tim e; th u s the i n a b i l i t y to m a in ta in p r e s s u r e s on th e c e l l and i t s c o n te n ts must b e a s c r i b e d to th e p l a s t i c flow p r o p e r t i e s o f th e sam ples and the n o n - m e ta llic m a t e r ia ls o f th e c e l l , o r b o th . The n a tu r e of the c u r d - f i b e r phase o f th e soap i s such t h a t 28 i t c o n s i s t a o f an opaque w h ite f e l t of c u rd f i b e r s . The b u n d le s o f i n t e r l a c i n g f i b e r s , r e p r e s e n ti n g as th e y do a f i n e c a p i l l a r y system o f v a r i e d pore s i z e s , would c e r t a i n l y be exp ected to d e fo m under p r e s s u r e in a n o n - e l a s t i c manner. The observed d e f o l i a t i o n o f the g a s k e ts and th e o th e r n o n - m e ta llic m a t e r ia ls makes i t p ro b a b le t h a t b o th o f the .. f a c t o r s above were re s p o n s ib le f o r the la c k o f c o n sta n c y of p r e s s u r e . - 8 8 - These system s were o r i g i n a l l y powders when p la c e d in th e c e l l , and were n o t f l u i d i n th e se n se o f t h e i r a b i l i t y to t r a n s m it p r e s s u r e e v e n ly . When p r e s s u r e was a p p lie d t h e r e must have been l o c a l sp o ts o f v e ry h igh p r e s s u r e . Even though th e evidence p o in ts to th e c o n c lu s io n t h a t a t th e via t e r c o n te n ts o f th e s e sam ples - n o t over 15% - most of th e w a te r must be presumed to be bound o r ' a t l e a s t o r ie n t e d a t th e p o l a r h eads, some o f t h i s w a te r can be squeezed o u t, a s w i l l be shown l a t e r . A g r e a t many q u e s tio n s can be a sk ed as to. what happens when th e p r e s s u r e i s a p p li e d , su c h as "Where does th e w a ter p r e s e n t go? There a re many dead ' a i r T ' spaces o f m acro sco p ic, and p o s s i b l y m ic ro sco p ic and su b -m icro sco p ic dim ensions i n t o w hich a f l u i d ' may be f o r c e d . At c e r t a i n c o n c e n tr a ti o n s , some o f th e w a te r i s sq u e ez ed to the in n e r . s u r f a c e s of the c e l l , a s s t a t e d above. Does s u r f a c e conduc t i v i t y th e n e n t e r i n to the p i c t u r e ? Is i t n e c e s s a ry t o c o n s id e r the a d s o r p tio n of w a te r a n d /o r th e soap s o l u t io n on th e s u r f a c e , an d i t s c o n d u c tiv ity ? Is i t n o t more th a n l i k e l y t h a t d i f f e r e n t 'e q u i l i b r i u m 1 c o n d itio n s e x i s t a t v a rio u s p r e s s u r e s w ith r e f e r e n c e to the d i s t r i b u t i o n of w a te r , w ith the p o s s i b i l i t y th a t a t c e r t a i n p r e s s u r e s the ' e q u i l i b r i a 1 s t a t e s c o n ta in w a ter betw een the p a r a f f i n c h a in s , and t h a t th e ra te s of a tta in m e n t of th e ' e q u i l i b r i a ' under no p r e s s u r e may be e x c e e d in g ly slo w ? ” A g r e a t number of s p e c u la tio n s a r e p o s s ib l e from - 8 9 - th e o b s e rv a tio n s and t h e c o n s i d e r a t i o n s above, which a re by no means e x h a u s tiv e . I t is t h e w r i t e r ’s c o n s id e re d o p in io n t h a t i t i s im p o s sib le to e v a lu a te the im p o rtan ce, even r e l a t i v e l y , of th e l a r g e number of f a c t o r s t h a t a r e a t p la y , and one i s fo rc e d t o c on clude t h a t i t i s to o much to e x p e c t to a t t a i n c o n s ta n t r e s i s t a n c e v a lu e s by p r e s s u r e tr e a tm e n t under th e e x p erim e n tal c o n d itio n s d e s c r ib e d . In c o n n e c tio n w ith the changes o f c om po sition o f th e samples d u rin g p r e s s u re tre a tm e n t* i t was d isc o v e re d t h a t i t was p o s s ib l e to low er th e w a te r c o n te n t of a sample from 9 .4 $ t o 4.8$' by k eep ing i t under 5000 pounds gauge p r e s s u r e for one hour’ a t room te m p e ra tu re * T his r e s u l t was o b ta in e d a f t e r i t was found t h a t when r e s i s t a n c e measurements a t v a ry in g te m p e ra tu re s were made on v a rio u s samples under p r e s s u r e , t h e w a te r c o n te n t o f t h e sam ples, i f o v e r a few p e rc e n t o r i g i n a l l y , d e c re a s e d . Thus i t i s p o s s ib le to a s c r i b e most of th e w a ter l o s s to th e p re s s u re tre a tm e n t r a t h e r th a n th e h e a tin g , a t l e a s t in t h i s ran g e of concen t r a t i o n s of w a te r . Samples w i t h l e s s th an a few p e rc e n t of w a ter i n c r e a s e d in w a te r c o n te n t d u rin g t h e c o u rse o f runs under p r e s s u r e . This phenomenon o c c u rre d even a f t e r p r e c a u tio n s were tak en to d ry a l l p a r t s o f th e c e l l in an oven f o r o s e v e r a l h ours a t 105 C b e fo re u s e . The d i f f i c u l t i e s above made i t a p p a re n t t h a t some a r b i t r a r y method o f p re s s u re tre a tm e n t was n e c e ssa ry in - 9 0 - o rd e r t o o b t a i n any u s e f u l c o n d u c tim e tric r e s u l t s * The p ro ced u re f i n a l l y adopted was t o p la c e th e sample a t the / lo w e st te m p e ra tu re a t which th e r e s i s t a n c e was m easurable under some p r e s s u r e a t which a f a i r l y c o n s ta n t r e s i s t a n c e measurement was o b ta in a b le * For most o f th e samples th e p r e s s u r e n e c e s s a r y was a few th o u san d pounds on th e g a u g e. A f te r t h e p r e s s u r e s e t t i n g on a sample had been made, t h e a d ju s tm a it on th e C arver P re s s was n o t d i s t u r b e d , even though t h e p r e s s u r e f e l l * T h e r e a f t e r , r e s i s t a n c e measurements were ta k e n as f o llo w s . The te m p e ra tu re was r a i s e d a c e r t a i n a r b i t r a r y number ,of d egrees a s q u ic k ly as p o s s i b l e , and k e p t th e re u n t i l a n a r b i t r a r i l y f ix e d time* Then th e p ro c e s s was r e p e a te d , r a i s i n g th e tem pera tu r e th e same number of d eg rees and a llo w in g th e same time i n t e r v a l to e la p s e between m easurem ents, and so on. The u su a l te m p e ra tu re and tim e i n t e r v a l s were 2° and 20 m in u te s. A p a r t o f th e sample not used to f i l l th e c e l l was a n aly zed f o r w a te r c o n te n t b e f o r e a run* A f te r th e ru n t h e c e l l was a llo w e d to come to room te m p e ra tu re , and a l l th e sam ple t h a t could b e c o n v e n ie n tly sc ra p e d out was a n a ly z e d f o r g ro s s w a te r c o n te n t. A nalyses were perform ed by d ry in g th e soaps to c o n s ta n t w eight a t 105°C. As i s to be ex p ec te d from th e f o r e g o in g , r e p r o d u c ib le LET c u rv e s were not a t t a i n a b l e ; even th e b re a k s in t h e cu rve d id no t always occur a t the same tem p era tu re s w ith d u p lic a te sam ples o f th e same s o a p . The d a ta from which th e LET cu rves - 9 1 - were drawn a re p r e s e n te d in T ables XYI and XXIY. A summary o f th e data and i n t e r p r e t a t i o n s a p p ea rs in Table XXY. This summary i s p r e s e n te d as o f p o s s ib le v a lu e to f u t u r e i n v e s t i g a t o r s in th e f i e l d , and because a m a jo r ity o f th e te m p e ra tu re s a t w hich " b r e a k s ” occur seem to a g re e c l o s e l y w ith 52° and 71°, te m p e ra tu re s a t which phase changes f o r anhydrous and s l i g h t l y hydrous sodium s t e a r a t e 24* have been d em o n stra te d . In t h i s c o n n e c tio n i t i s i n t e r e s t in g to n o te t h a t most of th e sam ples showed "b rea k s" in the LBT c u rv es a t th e a lp h a - b e ta t r a n s i t i o n te m p e ra tu re o f 52 • T here has been c o n s id e r a b le i n t e r e s t in th e c o n d itio n s under w hich t h i s t r a n s i t i o n i s r e v e r s i b l e . A ll of th e sam ples i n t h i s s e r i e s were p re p a re d by h e a t in g th e p ro p er amounts o f soap and w a te r to th e i s o t r o p i c l i q u i d , homogenizing a t abo u t 300°C, and a llo w in g them t o coo l to room te m p e ra tu re i n a c lo s e d oven. Thus th e y were above 52° a t one time* b u t showed th e t r a n s i t i o n upon h e a tin g through t h a t tem pera t u r e , i f i t be g ra n te d t h a t th e " b re a k s" may be i n t e r p r e t e d as phase changes. This i s c o n tr a r y to what one w ould expect 24 from the g e n e r a l i r r e v e r s i b i l i t y of the t r a n s i t i o n . However, th e p r e s e n t e x p erim e n tal f a c t s a g re e w ith an •' 32 o b s e r v a tio n of M . J . B u erg er and h is c o -w o rk ers, who o b ta in e d a lp h a sodium s t e a r a t e by h e a tin g b e ta in a s e a le d *B eference 24 c o n ta in s r e f e r e n c e s to e a r l i e r work on th e s u b j e c t . - 9 2 - TABLE XVI EESISTANCES OF SODIUM STEABATE 0 I n i t i a l . W ater C onten t - 0.44 $ F i n a l W ater Content - 0*74$ I n i t i a l Gauge P re s s u re - 5000 lbs* F i n a l Gauge P r e s s u r e - 3300 lbs* H eating r a t e - 3° p e r i / 2 hour Measurements a t 415 c y c le s B-ohms 6 2 ,0 6 5.0 67,9 71.0 74.0 77*0 79 .-9 83 .2 85.7 89.1 92.0 95.1 97.0 9 8.0 3 SOM 28 5M 240M 173M 14 2 M 1 1 4 . s i 8 4 .O M 55. m 46 . 7M 39 .4M 2 9 .2M 2 1 . 2M 1 9 . 3M 1 9 .1M TABLE X V II EESBTAKCES OF SOLIUM STEARATE P I n i t i a l Water C ontent - 0*48$ F i n a l W ater C ontent - 1 .0 6 $ I n i t i a l Gauge P re s s u re - 5000 lb s* F in a l Gauge P re s s u re - 4000 l b s . H e a tin g H ate - 2 ° -per l/B hour Measurements a t 415 c y c le s T°C B-ohms 47*9 1 ,122M 50.0 850M 50.0 922M 52.0 700M 54.0 600M 56.0 60 O M 58.0 50GM TABLE X V III BESISIAUCES OF SODIUM STEARATE Q I n i t i a l W ater Content - 0*98% F i n a l W ater C ontent * 1*10$ I n i t i a l Gauge P r e s s u r e - 3000 lbs.- F in a l Gauge P r e s s u r e - 2000 l b s . H eatin g H ate - 2° p e r 20 m inutes Measurements a t 415 c y c le s 0 T 0 B-ohms 46 880M 4 7 .8 80 OM 49 .8 700M 51 .8 600M: 55.8 540M 56.2 460M 5 8.0 51 OM 60 .0 265M 62.5 25 OM 64.2 205M 66.5 180M 6 8 .2 140 M 70.2 124M 72.1 119M 74 .4 98M - 9 5 - TABLE XIX B E 3I SEANCES OF SODIUM STEABATE B I n i t i a l W ater C o n ta it- F i n a l W ater Content - 0 .9 3 $ , tak e n 48 h o ars a f t e r ^he d a ta shown* and subseq u en t to a n o th e r run to 41 a t 5000 l b s . gauge p r e s s u r e . ( L a t t e r d a ta n o t shown i n t a b le ) I n i t i a l Gauge P re s s u re - 5Q00 lb s* F i n a l Gauge P re s s u re - 3500 l b s . o / H e atin g B a te - 3 p e r 1/E hour a t 415 c y c le s T°C H-ohms E5 763M 28 538M 31 37 2M 34 322M 36 .8 239M 40*3 206M 43.0 171. m 46.0 1 4 1 .9M 4 9 .1 1 0 7 .1M 52.0 92.414 52*0 8 8 .OM 55.0 7 9 .1M 55.1 7 6 .1M 55.0 7 5 .6M 58.1 64*711 6 0.8 5 6 .5M 64.0 4 5 .4M 67.0 39 .7M 70.0 ;•35.7M 73.2 3 2 .O M 76.0 3 1 . m 78.8 2 9 .1M - 9 6 - EABLE 3X1 EESIffiDAHCES OF SODIUM STEASATE S I n i t i a l W ater Content - 3#47$ F in a l W ater C ontent ~ 3 .4 0 $ I n i t i a l . Gauge P r e s s u r e - 3000 l b s . F i n a l Gauge P re s s u re - £000 lb s* H e a tin g H ate 2° p e r 20 m inutes Measurements a t 415 c y c le s T C 52 .0 32*0 34.3 36.0 37.7 39.7 41*7 43*6 4 6 .0 48.3 50.1 52*0 54.5 56> *6 58.7 6 0 .5 B-ohms 95M 95M 20M 78M 71*5M 64. 5M 5 7 .OM 50. 5M 4 3 .5M 39. OM 3 4 .5M 31 .OM 28. OM 24. 7M 21. 3M 18. 9M - 9 7 - PAB1E XXI B IS IS M T C E S OF SODIUM STEABA1E T I n i t i a l W ater 0o n te n t - 3*60% F i n a l W ater Content - 3.73$ I n i t i a l Gauge P r e s s u r e - 3000 l b s . F in a l Gauge P r e s s u r e - 2500 l b s . H e a tin g B a te - 2° p e r 20 m inutes M easurements a t 415 c y c le s C l B-ohms 29 *8 280M 31.8- 27 5M 33.9 26 5M 35.4 260M 37.2 250 M 39.7 235 M 4 1 .3 225M 43.4 208 M 45.6 192M 4 7 .7 178M 50.0 160 M 51.8 148 M 53.9 124 M 55.9 114 M 57 *9 102 M 6 0 .1 89 M 62 .0 80 M TAB'IE 2X II IffiSISTAJSGES O F SODIUM STEARATE U I n i t i a l W ater C ontent - 3*50$ Final. W ater Content - 3*31$ I n i t i a l Gauge P r e s s u r e - 5000 I t s . F in a l Gauge P r e s s u r e - 4000 I t s , H eating H ate - 2° p e r l / 2 hours M easurements a t 415 c y c le s T°C H-^ohms 35*5 l t 222M 3 7 .5 l t 172M 40*0 1 , 022M 41*3 952M 43*3 872M 4 3 .3 830 M 45.9 700M 4 8 .0 620 M 50.0 600M 51.8 550M 54.0 430M 56.0 370M 58.1 280M - 9 9 - TABLE X X III BESISTAHCES OF SODIUM S O I MB: ATE V I n i t i a l Water Cant a it - 1 3 .2 $ F in a l- Water O ontent - 4*0% P r e s s u r e H is to r y - At room te m p e r a t u r e f a p r e s s u r e o f 5000 pounds was a p p l i e d , and r e l e a s e d a f t e r a few m in u te s. The c y c le was r e p e a te d about s i x tim e s d u rin g 30 m in u te s . A f te r r a i s i n g th e p r e s s u r e to 5000 pounds a g a in , i t dropped to 3000 pounds i n 2 h o u rs. The sample was h e a te d to 30 .4°C t and d u rin g th e c o u rs e of th e n e x t h a lf - h o u r p r e s s u r e was r e l e a s e d and r e - a p p l i e d s e v e r a l dozen tim e s , to v a lu e s ra n g in g from 2000-5000 pounds. P re s s u re to 3000 pounds was th e n a p p lie d , and th e system allow ed to s ta n d f o r 40 hours a t room te m p e r a tu re . P r e s s u r e was th e n a p p lie d to s e v e r a l thousand pounds and r e l e a s e d , and th e p ro c e s s re p e a te d s e v e r a l tim e s. Then a p re s s u re s u f f i c i e n t t o g iv e a r e a c t i o n on th e pumping le v e r o f th e C arver p r e s s — b u t n o t to show on th e gauge— was a p p l i e d , and m easure ments made as t a b u l a t e d below . H e a tin g B ate - 3° p e r 1 /2 h o u r. Measurements a t 415 c y c l e s . T°C B-ohms T°C B-ohms 24 3550 54.5 1450 ' 27 3230 57.0 1350 30.3 2900 6 0 .0 1 2 2 0 33.1 2680 63.3 1090 36 .0 2480 6 6 . 8 980 39.0 2270 6 9 .1 890 4 2 .0 2 1 0 0 73.0 795 4 4 .5 2 0 0 0 76.6 720 4 6 .8 1830 8 0 .0 650 50.5 1670 8 3.6 600 -100* TABLE XXIV BES3BTAHCES OF SODIUM STEABATE W I n i t i a l W ^ter 0 o n te n t - 13*2$ F in a l Water Content - 3*6$ P r e s s u re H is to r y - P r e s s u r e was a p p l i e d to 2500 pounds, and r e - a p p l i e d to t h a t v a lu e whenever i t f e l l below 2 0 0 0 pounds d u rin g th e f i r s t ru n . T his was n e c e s s a ry f i v e times* H e a tin g was th en d is c o n tin u e d , and f i f t e e n hours l a t e r th e p r e s s u r e , which had f a l l e n to below th e l i m i t o f the gauge* was ,r a is e d t o 3000 pounds. D uring the second r u n , th e p r e s s u r e was r a i s e d to 3000 pounds when i t f e l l below 2500 pounds* T his was ne c es s a r y ei g h t t i mes • H e a tin g B a te - a b o u t 2° p e r 20 m inutes f o r b o th r u n s . M easurements a t 415 cycles . T°C F i r s t B B-ohms B-ohms T°C B-ohms Second Bun - B-ohms 25 3 7 . 7M 5 3.4 34.0M 2 0 21.7M 56.0 32 *5M 27 51w5M 55.8 26. 6 M 23 271M 58.2 2 5 .1M 29 6 0. 9M 57.7 2 3 .1M 26 2 6 2 .5M 61.0 2 0 . 3M 31 6 5 .9M 6 0 .5 1 7 .OM 29 234M 6 3 .0 1 6 . 7M 33.2 6 9 .9M 6 3.2 13. 2M 32.5 213M 65 .2 1 3 .7M 3 5.1 7 6 .6M 6 5 .5 1 0 . 5M 35,0 1 7 7 .5M 6 8 . 0 1 0 , 5M 37.1 76 . 6 M 6 8 .5 7800: 3 8 .0 162.5ft 70.5 8600 4 0 .0 8 1 .6M . 71.0 6400 39.5 1 4 2 ,2M 73.0 6750 4 2 .1 7 7 . 6 M 74.0 530 0 41 .0 1 2 4 .6M 7 6 .5 5750 44* 5 6 8 . 7M 7 6 .2 4600 4 3 .2 1 0 1 .5M 79.5 4990 46 * 6 5 9 .5M 78.3 4200 4 5 .2 8 4 .OM 82.2 4380 49.4 50. 4M 8 1 ,0 3900 4 8 .2 5 9 .5M 8 5.0 3990 51.2 41 .OM 83.2 3600 4 8 .2 5 9 .5M 8 8 . 0 3620 51.0 51 .OM 9 0.2 3450 5 3.2 4 1 . OM 94.0 3210 " -jo ; - T A B L E X X V SUMMARY OF CONBUCTIMETRIC RESULTS WITH SODIUM STEARATE-WATER SYSTEMS IN PLUNGER CELLS Data in Table XVI XVH XVIII IX XX XXI XXII Water Content Before A&er Rim Run 0.44# 0.74# 0.48 1.06 0.98 1.10 0.93 3.47 3.40 3.60 3.73 3.50 3*31 XXIII 13.2 4.0 XXIV 13.2 3.6 Temperatures of "Breaks^ iii the flLRT1 1 curves 4 ... : ' ‘ ' 77°, 83°,, 89° 52 Additional Observations 56°, 66°, 72° 51°, 73° 52° 52 48°, 52° 51°, 69° 50°, 71° Definite flattening off of the ”LRT” curve at 95°. The ’ ’ break” noted is doubtful. The ’ ’ break” at $6° is a discontinuous'8' one. The ' ’ break1 1 noted is discontinuous.* The’ ’ break” noted is discontinuous .* The two temperatures noted represent the' beginning and end of a ’ ’ hump” in the ”LRT” curve. (These samples had long (and varied, but different (pressure histories before (the runs, as shown in (Tables XXIII and XXIV, * That is, there are discontinuities in the LET curves at these temperatures* -102 - 24 tu b e w i t h a drop o f w a te r a t 47°C. B . D. T o ld a l s o r e p o r t s th e r e - f o r m a tio n o f a sm a ll amount o f a lp h a i n a c a l o r im e te r c e l l a f t e r h e a tin g above 52° and c o o lin g t o room tem p eratu re* I t i s th e w r i t e r ' s o p in io n t h a t ; (1) C e lls o f the ty p e d e s c r ib e d , w ith p o s s ib l y r a d i c a l m o d if ic a tio n s , co u ld be used to o b ta in im p o rta n t c o n d u c tim e tr ic d a ta on so a p -w a te r system s; and ( 2 ) a stu d y d i r e c t e d a t th e e f f e c t s of p re s s u r e on o th e r p r o p e r t i e s o f such system s could w e l l le a d to mew and s i g n i f i c a n t d i s c o v e r i e s . - 1 0 3 - CHAPTER V CONDUCTIVITIES OF TEE SODIUM STEARATE - W ATER SYSTEM IE THE MI DELE SOAP AND SOAP BOILER’ S NEAT SOAP REGIONS f The b o u n d a rie s o f th e tw o-phase r e g io n c o n n e c tin g th e i s l a n d p h ases of m iddle soap and soap b o i l e r * s n e a t soap 2 s r a r e i m p e r f e c tl y known* S e a le d " p a r a l l e l - w i r e c e l l s were i n d i c a t e d f o r a c o n d a c tim e tric s tu d y in t h i s re g io n , sin c e p re v io u s ex p erien ce (C h ap ter IV) had pro v en th e inadequacy o f s e a l i n g a ff o r d e d by th e " p r e s s u r e ” c e l l s a t th e te m p e ra tu re s and co m p o sitio n s o f th e b o u n d a rie s under c o n s i d e r a t i o n . Whether i t i s p o s s ib le f o r such a stu d y to e s t a b l i s h the above-m entioned phase b o u n d a rie s depends on th e r e l a t i v e c o n d u c t i v i t i e s o f the two p h a se s. These c c m d u c tiv itie s w ere d eterm in ed as d e s c r ib e d below. A. E xp erim ental • Two system s o f sodium s t e a r a t e w ith medium p e r c e n ta g e s o f w a te r (2 8 .7 $ and 69.3$) were p re p a re d and homogenized in " p a r a l l e l - w i r e ” c e l l s i n a manner s im il a r to t h a t d e s c rib e d i n C h ap ter I I , excep t t h a t g la s s rods were n o t n e c e s s a r y b ecau se o f th e low er te m p e ra tu re s under i n v e s t i g a t i o n . S e v e ra l a tte m p ts t o homogenize th e f i r s t sample r e s u l t e d i n blowm-up c e l l s b e fo re t h e tem p eratu re of hom ogenization, a b o u t 2 80°q f 0r t h i s w a te r c o n te n t. F i n a l l y th e sample was s u c c e s s f u l l y homogenized b y adding - 1 0 4 - a weighed amount o f a 13*5$ sam ple, p r e v io u s ly homogenized i n a n o th e r tu b e , to s u f f i c i e n t w a te r i n a c e l l l i k e C ell A {Chapter IY) and hom ogenizing in the u su al f a s h i o n . The 69 .3 $ w a te r sample was homogenized j u s t below 200°C w ith o u t • m ishap, in an o r d in a r y c e l l w ith tu n g s te n e l e c t r o d e s , as d e s c r ib e d i n C hapter I I . The c e l l c o n s t a n t s were E . 1 0 and 1.32 r e s p e c t i v e l y , and a l l r e s i s t a n c e m easurem ent^ which were made a t 960 c y c l e s , were reduced to s p e c i f i c r e s i s t a n c e s . Buns were made by h e a tin g in th e oven d e s c rib e d i n C hapter I I . Tem peratures w ere measured w ith a c a l i b r a t e d therm om eter re a d in g to o .l° C . The r e s u l t s a re t a b u la te d in T ab les XXVI and XXVII, and p l o t t e d on th e customary LET axes i n F ig u re s XVII and X V III. 2 * R e s u lts above 80°C. At e q u ilib riu m above 90° the 2 8 .7 $ w a ter sample i s known to be soap b o i l e r ' s n e a t so a p , and above 80° th e 6 9 .3 $ w a te r sample, m iddle so a p ; and i t was f o r t h i s re a so n t h a t th e s e c o m p o sitio n s were c h o sen , and th e sam ples r e f e r r e d to a s "Kn and ”MI T r e s p e c t i v e l y . Whereas Sample N showed th e s o f t e n in g and c l e a r i n g a s s o c i a t e d w ith the form a t i o n o f n e a t soap a t 89°Cat th e to p of th e sam ple, the p ro c e ss was n o t com plete aro und th e bottom a t th e e l e c t r o d e s o u n t i l 111 C. No re a s o n a b le e x p la n a tio n f o r t h i s b e h a v io r i s a p p a re n t t o t h e w r i t e r , s in c e f r a c t i o n a t i o n o f t h i s d ense sample seems im probable, and t h e absence of s ta n d in g - /05- TABLE x m SPECIFIC RESISTANCES OF SODIUM STEARATE M 69.3# Water - 960 Cycles First Rian Heated about 1° per 5-6 minutes from room temperature . T°C 32.5 34*5 36.5 38.5 40.5 42.5 44.5 46.5 48.5 50.5 52.5 54.5 56.5 59.5 60.5 62.5 65.5 67.5 69.5 71.5 73.5 74.5 75.5 77.0 79.0 80.0 83D 82.5 84.5 86.0 87.5 700 675 660 670 623 565 575 540 520 510 460 450 460 465 460 445 425 215 158 117 71 62 50 42 37 37 37 Second Run Heated about 1° per 5-6 minutes from room temperature. T C R—ohms T C T°e R-ohms T°C 41.0 790 . 103 43.5 730 160 47.0 49.0 685 660 51.0 650 53.0 635 56.0 630 58.5 585 61.0 540 63.0 540 65.5 540 67.0 515 69.0 515 71.0 450 73.0 375 74.0 225 Third Run Other observations made with good electrode- contact at higher tempertures R-ohms 29 33 _ fO ( e > ~ T A B L E m i l SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E N i 28*7% Water - 960 Cycles First Run about I per £-3 minutes from room temperature Second Run Heated about 1° per 3-6 minutes from room temperature Third Run Heated about 1° per 5-6 minutes from room -temperature T°C R-ohms T°C - R-ohms T°C R-ohms 7 3 2 3 0 0 2 8 .5 5 4 0 0 41.0 3 9 8 0 7 9 1200 30.5 5 1 3 0 4 3 .5 3 6 4 0 8 3 7 8 5 32.5 4 9 7 0 47.0 3 2 5 0 86 250 343 4 7 1 0 49.0 3010 8 9 220 36.5 4 5 0 0 5i ; o 2 9 3 0 9 3 1 4 1 38.5 ' 4 2 9 0 53.0 2780 9 5 1 3 1 40.5 4080 56.0 2 9 3 0 9 7 1 0 5 42.5 3 8 5 0 5 8 ; 5 3 0 4 0 101 7 8 44.5 3 6 7 0 61.0 3 1 7 0 1 0 4 60 46.5 3 4 0 0 65.0 3120 1 0 8 5 0 48.5 3 1 9 0 67.0 2 9 9 0 in 4 5 5 o ;5 3080 69.0 2830 n5 4 5 5 2 * 5 2 8 8 0 71.0 2500 ll9 3 9 54.5 2 9 3 0 73.0 2200 1 2 3 3 7 5 5 * 5 3010 74.0 1980 1 2 7 3 7 56.5 3060 1 5 5 3 2 5 7 .5 3 1 4 0 170 3 2 58.5 3 1 9 0 5 9 i5 3250. 60.5 3 3 5 0 62 .5 3 2 5 0 65.5 3 1 9 0 67:5 3 1 4 0 69.5 2 9 3 0 7 1 * 5 , 2 5 7 0 73.5 2200 7 4 * 5 1 9 9 0 7 5 * 5 1830 77.0 I56O 79.0 1 3 1 0 80.0 noo 81.0 9 4 0 82 .5 7 1 0 84 .5 4 4 5 86.0 260 87.5 2 1 5 F .'9 . 'E2IL R € t» I .3 t o i « Cfc! i o f M «S C b t ^ 6 9. 3 % FLO O F, v j■ f. v ^ y I A • -S e c < 3 ^ ^ ' Crl . CD f i e u - v j f 1 0 v\ j J < 1 Wl^ k. J O c.J CO «f*4 „ • U 1 ^ tv # k ' 'C « U v pe k - ^ 4 v r l/e i . 9 6 0 C j J . b O kw j -/oS~ M O 5 2 ° 6 6 ' 5* ! 0 3 O G fO I 2-10 M O 3 500' v ? e s £ o 8 0 F i j - . XV7TT 3 piCi ^ ic Re , c> ( N * S ir N Z & .7 % H.,0 9 6 0 C ' y J i J rn f«»"^^ o s e c o ux<J * " < / r T F i r J v- U ia (3 o^\e t < * f c o / ^ i € .J O K A i ' t l e - J ( o / -s^Ue. 5? ° Or Q C ’ 8 2 -1 0 * 8 G 0 a. 'O I‘ (0 : 5*10' % 1 1 2 D ED 0 f 03 0 0 2 - 1 0 * 10' J____ L 20 40 6 0 ao 1 0 0 1 2 0 •< st u T e t- n p e r d tuv^c. ° C - (40 160 (60 - 1 0 9 - tempera t a r e g r a d i e n t s i n th e oven has heen dem onstrated p r e v i o u s ly in C hapter I I , page 30* Sample M shows th e o o expected "break i n t h e LET carv e a t 83 C, w i t h i n 3 C of th e l i t e r a t u r e v a l u e . During a n o th e r run (not shown i n th e Tables), Sample M showed v e ry h igh 'and e r r a t i c v a lu e s o f r e s i s t a n c e u n t i l 160°C. D uring th e h e a tin g to t h a t te m p e ra tu re many b u b b le s su rro und ed th e e l e c t r o d e s * The b u b b le s th en d isa p p e a re d f o r a few seconds, re -fo rm e d a g a in , and t h i s e r r a t i c b e h a v io r p e r s i s t e d . Changes o f r e s i s t a n c e c o r r e l a t e d w ith bubble fo rm a tio n and d is a p p e a ra n c e . C ooling the sample r a p i d l y to room te m p e ra tu re by .'removing i t from th e oven in to th e room allow ed the su b seq u e n t " f i r s t " ru n . In an e f f o r t t o e s t a b l i s h th e s o a p - b o i l e r 's n e at s o a p -s u p e rn e a t soap boundary, a tte m p ts were made t o m easure th e r e s i s t a n c e s o f sample H above 180°. These were u n su c c e ss f u l b ecau se o f foam ing and th e e v o lu tio n o f b u b b les from th e e l e c t r o d e s . In s p i t e of th e s e d i f f i c u l t i e s i t i s p o s s ib le to give an answ er to th e main purpose o f t h i s p a r t o f th e i n v e s t i g a t i o n , t h a t i s , to determ ine th e r e l a t i v e c o n d u c t i v i t i e s o f n e a t and middle s o a p . These seem t o be i d e n t i c a l a t above 1B0°C and p ro b a b ly lower* w ith t h e v a lu e o f j u s t over 30 ohms f o r th e s p e c i f i c r e s i s t a n c e in th e ra n g e 120°G - 160°C, and w i t h a sm all te m p e ra tu re c o e f f i c i e n t . Thus i t would seem t h a t an a tte m p t to determ ine th e b o u n d a rie s o f th e tw o-phase r e g io n betw een soap b o i l e r ' s n e a t soap and m iddle soap by a - 1 1 0 - c o n d u c tr im e tr ic method would be u n su c c e ss fu l* I t i s q u i t e s i g n i f i c a n t t h a t a 1 2 .8 $ w a te r sample (Sample K, C hapter IV) has a 36 ohm s p e c i f i c r e s i s t a n c e above 140°C, w ith a sm a ll te m p e ra tu re c o e f f i c i e n t t h e r e a f t e r ; t h i s o b s e rv a tio n coupled w ith th e r e s u l t s above makes i t a s t r o n g p resum p tion t h a t above T and in th e o range of a t l e a s t 13-70$ water* th e s p e c i f i c r e s i s t a n c e may be in d ep en d en t o f w a te r c o m p o s itio n . (✓ ♦ Phase I m p lic a tio n s a t Lower T e m p e ra tu re s. The r a t h e r i n t e r e s t i n g l1humpH i n th e LPT curve t h a t a p p e a rs in th e 1 2 .8 $ sample (Sample K, C hapter IV) a t 50°- 60°C re a p p e a rs a t 52 °- 6 6 °C i n sample N* and t o a l e s s e r degree a t 60° - 72°C in sample M * b u t a t w id e ly d i f f e r i n g v a lu e s , 600Q* 3000* an d 450 ohms r e s p e c t i v e l y . B oth t h e b e g in n in g s and t h e p e ak s o f th e "humps" suggest phase changes* E x te n sio n s to t h e l e f t o f the e u te e to id f l a t s co n n ectin g i s o t r o p i c s o l u t i o n to m iddle soap* and m iddle soap to soap b o i l e r * s n e a t so ap , as diagrammed below , p r e d i c t 76° and 82°C, i £ < © V . X £ £ S o a fc > Boiler^ MidMt ■ ISotvobtc Li<wi4, Com^ositioh. - W eijK t percent /VdStr - 1 1 1 - r e s p e c t i v e l y , as te m p e r a tu re s .of' phase changes* (These f l a t s * a lth o u g h r e q u ir e d by the phase r u l e , a re n o t confirm ed I o by th e p r e s e n t s tu d y , n o r by c a l o r i m e t r i c or r h e o l o g i c a l i n v e s ti g a t i o n s * The l a t t e r s t u d i e s a l s o i n d i c a t e changes below abo u t 75° • Such a l a c k o f evidence r e g a r d i n g th e e x is te n c e of the. e x te n s io n s o f th e s e f l a t s makes i t re a so n a b le to c o n s id e r ( th e p o s s i b i l i t y t h a t o th e r i s l a n d p h ases tentim ate th a n , and t h a t th e changes found i n th e p r e s e n t and o th e r i n v e s t i g a tio n s m entioned above are r e l a t e d to th e s e i s l a n d p h a s e s . In d ee d , Ferguson has ev id en ce f o r th e e x is te n c e o f a " d e l t a ? p h a se , whose fo rm a tio n i s f a v o f e d b y .high w a te r c o n te n t and c o o lin g from i s o t r o p i c l i q u i d , „ a t l e a s t in th e c a s e of sodium s t e a r a t e * These a r e p r e c i s e l y t h e c o n d itio n s of form a t i o n o f tine samples s t u d i e d in th e C o n d u c tim etric and c a l o r i m e tric i n v e s t i gat ions . Another i n t e r e s t i n g s p e c u la tio n i s t h a t the e u t e c t o i d f l a t s m ight n o t a p p e a r under th e e x p e rim e n ta l c o n d itio n s of t h i s r e p o r t b ecau se of th e fo rm a tio n o f m e ta - s ta b le s t a t e s upon c o o lin g o f th e samples a f t e r th e y had b e e n homogenized a t h ig h e r te m p e r a tu re s . The r e p o r te d e f f e c t s o f m echanical a g i t a t i o n , t h e te m p e ra tu re o f a g i t a t i o n , r a t e s of c o o lin g , and ag in g on th e x - r a y , r h e o l o g i c a l , and o t h e r . p r o p e r t i e s o f /a such system s in t h i s te m p e ra tu re -c o m p o s itio n ran g e i s s u f f i c i e n t re a so n t o c o n s id e r su c h a s p e c u l a t i o n . The w r i t e r i s o f the o p in io n t h a t the p r e s e n t d a ta . a re too meager to w a r r a n t f u r t h e r a tte m p ts a t i n t e r p r e t a t i o n , - 1 1 2 - b u t i t i s e v id e n t t h a t f a r t h e r c o n d u c tim e tric work i n th e r e g i o n under c o n s id e r a tio n sh o u ld prove to be o f c o n s id e ra b le a i d in c l e a r i n g some- o f i t s p r e s e n t p e r p le x in g problem s. SUMMABY - 1 1 4 - E l e c t r i c a l c o n d u c t i v i t i e s of a n hyd rou s, pure sodium p a lm i ta te a n d s t e a r a t e , and of c o n c e n tra te d system s o f th e l a t t e r in w a te r , were measured as f u n c t i o n s of tem p e r a t u r e and w ater co n te n t* Measurements were made w ith an a l t e r n a t i n g c u r r e n t W heatstone B rid g e ; th e so urce o f c u r r e n t was an a u d i o - o s c i l l a t o r o f v a r i a b l e fre q u e n c y , and th e n u l l - p o i n t i n d i c a t o r a vacuum tube a m p l i f i e r i n c o r p o r a tin g an " e l e c t r i c - e y e " tube* For anhydrous sodium p a lm i ta te in a s e a le d g la s s c e l l w i t h p la tin u m w ire s as e l e c t r o d e s , s e v e r a l im p o rta n t f a c t s were e s t a b l i s h e d . ( l ) As th e te m p e ra tu re was r a i s e d conductance was f i r s t m easurable a t 239° (a t a v a lu e of ab out 1 0 “ 6 mho); ( 2 ) "b re a k s" i n th e s lo p e s of th e l o g a rith m of r e s i s t a n c e v s . te m p e ra tu re (LRT) c u rv e s o c cu rred s u b s e q u e n tly a t 256° and 295°G; (3) a d d itio n s o f l e s s t h a n 1 f o w a ter to th e soap low ered q u ite m arkedly th e te m p e ra tu re a t which conductance was f i r s t m easu rab le; and (4) w ith in re a s o n a b le l i m i t s , th e same r e s i s t a n e e - te m p e ra tu re values were o b ta in e d upon h e a tin g and c o o lin g . Item s ( l) and (3) showed t h a t th e c e l l s and e q u ip ment used were s u i t a b l e f o r stu d y in g c o n c e n tr a te d system s o f so ap in w a te r , p a r t i c u l a r l y a t h ig h e r te m p e ra tu re ^ , b u t a l s o a t low er te m p e ra tu re s a f t e r a d d it i o n s of sm all p e rc e n ta g e s o f w a te r . Items (2) and (4) f u r t h e r showed t h a t d a ta o b tain ed in su c h s t u d i e s could be used f o r d e te rm in a tio n s of phase ch an ges, s in c e 239°, 256° and $95° - 1 1 5 - a g re e w e ll w ith p r e v i o u s ly e s t a b l i s h e d phase t r a n s i t i o n s a t .237°, 253°, and 296°, r e s p e c t i v e l y . C o n d u c tiv ity measurements were made on ele v en sam ples of sodium s t e a r a t e w ith w a te r c o n te n ts ra n g in g from 010 to 1 2 . 8 $ . The c e l l s used c o n s is te d of p a r a l l e l Kovar or tu n g ste n w ire s s e a le d i n t o t h e b o tto m s-o f tubes' ^ of ’ .iPyrez g l a s s e s w ith th e p ro p e r c o e f f i c i e n t s o f expan sion* A f t e r a d d it i o n s of w eighed amounts of soap and w a te r , th e c e l l s were s e a le d , and th e c o n te n ts homogenized by h e a tin g them to t h e te m p e ra tu re of fo rm a tio n of th e i s o t r o p ic l i q u i d , above about 290°C f o r th e s e sam ples. In a s e r i e s of e x p lo r a to r y exp erim en ts i t was shown t h a t , a t r a t e s o f heating: f a s t e r than 1 ° p e r 2 or 3 m in u te s, " b re a k s " i n th e LET c u rv e s o ccu rred a t h ig h er te m p e ra tu re s th an th o se o b ta in e d f o r slo w er r a t e s of h e a t in g . Because of t h i s f a c t and th e p o s s i b i l i t y of u n d e rc o o lin g , most o f th e runs were made as the te m p e ra tu re in c re a s e d about 1° p e r 3 or 4 m in u te s. The. te m p e ra tu re s of th e " b re a k s " , r a t h e r th a n th e a b s o l u te v a lu e s of th e s p e c i f i c r e s i s t a n c e s , were used f o r most of th e i n t e r p r e t a t i o n s in t h e r e p o r t . O ften the a b s o lu te v a lu e f o r ‘th e s p e c i f i c r e s i s t a n c e of a given sample a t a giv en te m p e ra tu re v a rie d c o n s id e r a b ly from run to ru n , but in g e n e r a l the la c k of a b so lu te r e p r o d u c i b i l i t y d id not a f f e c t the te m p e ra tu re s a t which th e " b re a k s ” ap p ea re d i n the LRT c u rv e s. F a c to r s w hich may have a f f e c t e d - 1 1 6 - the r e p r o d u c i b i l i t y o f th e a b s o lu te v a lu e s o f r e s i s t a n c e s were eonsir dered and d is c u s s e d , The tem p erature o f th e phase change from su ^ n e a t to n e a t soap f o r th e anhydrous sample has been e s t a b l i s h e d p r e v i o u s ly a t S57°G by d i l a t o m e t r i c and h o t-w ire m ethods, A sharp, " b re a k ” in th e I»RT curve a t 255°C a g re e s w e ll w ith th e tem p era tu re of t h a t t r a n s i t i o n * This f a c t , to g e th e r w ith th e s i m i l a r r e s u l t s o b ta in e d f o r anhydrous sodium p a lm i ta te , made i t p o s s ib le to p o s t u l a t e t h a t a b r e a k in an LRT curve c o rre sp o n d ed to a change in p h ase. The " b r e a k s ” o b ta in e d on th e LRT c u rv e s of the e le v e n sodium s t e a r a t e sam ples w ere c l a s s i f i e d and ta b u l a t e d , and th e p o in ts above 1 0 0 °C p l o t t e d on a co m p osition v s , te m p e ra tu re diagram . P o in ts from l i t e r a t u r e so u rc e s wereaLso in c o r p o r a te d . The n a tu r e of the v a rio u s " b r e a k s , ” t h e i r a p p ea ra n c e, changes, and d isa p p e a ra n c e s as fu n c tio n s of w a te r c o n te n t and te m p e ra tu re , com parative c o n d u c t i v i t i e s of c e r t a i n p h a ses, and th e a p p l i c a b i l i t y of the phase r u l e were a l l c o n s id e re d in some d e t a i l in e s t a b l i s h i n g th e phase b o u n d a r ie s . The diagram d e f i n i t e l y e s t a b l i s h e d ' c e r t a i n phase b o u n d a rie s , and i n d ic a t e d a t l e a s t th e b e g in n in g d i r e c t i o n s f o r o th e r s .; In th e r e g io n of 170° - 300°C, and below 5fo w a te r, th e phase diagram showed "tongues" of th e n e at soap and su b n e at soap e x ten d in g in to about 4$ w ater c o m p o sitio n . This type of c o n s t r u c t io n has been e s t a b l i s h e d fo r sodium - 1 1 7 9 m y r is ta t e and o th e r soaps by v i s u a l and m icroscop ic means . The e a r l i e r b e l i e f o f s e v e r a l i n v e s t i g a t o r s t h a t th e s e phases p e r s i s t to a b o a t 1 0 $ w a ter f o r th e sodium s t e a r a t e - w a ter system was shown to be i n c o r r e c t . Phase b o u n d a rie s in th e re g io n of 100° - 140°C, and below 6 $ w a te r , were p r e s e n te d i n acco rd an ce w ith the f a c t s o b ta in e d and th e i n t e r p r e t a t i o n s of the c o u rse s cf the. LRT c u rv e s . I t was shown t h a t more work i s needed in the l a t t e r re g io n to c l a r i f y th e phase p i c t u r e . A mechanism f o r conductance in th e su bneat r e g io n was p r e s e n te d , namely, t h a t th e sodium io n s a re the only con d u ctin g s p e c i e s , and t h a t conductance ta k e s p la c e by t h e i r moving from m ic e lle to m ic e l l e . The mechanism i s b ased upon i n t e r p r e t a t i o n s of th e fo llo w in g : ( 1 ) th e la c k o f frequency-depend en ce of th e co ndu ctan ces i n th e range o f 42Q--7800 c y c l e s , th u s e lim in a tin g th e p o s s i b i l i t y of th e c o n t r i b u t i o n of d i p o la r r o t a t i o n , ( 2 ) th e presumed mice l i a r arrangem ent i n the su b n e at p hase, (3) t h e un f e a s i b i l i t y of e l e c t r o n conductance, (4) th e abrupt, changes i n s lo p e s of th e LRT curves a t th e su b n e at to n e a t soap t r a n s i t i o n , and (5) the v a lu e s of A and E c a l c u l a t e d from th e A rrh en iu s e q u a tio n , a p p li c a b l e to io n ic c o n d u c ta n c e s. The r e l a t i v e co ndu ctan ces o f sodium s t e a r a t e - w a te r system s were determ in ed in the s o a p - b o i l e r l s n e a t soap and m iddle soap re g io n s * ^ he' co n ductances were measured i n c e l l s of th e typ e used f o r th e h ig h -te m p e ra tu re - 1 1 8 - m easurements above. Two sam ples o f £ 8 .7 % and 69#3$ w ater c o n te n t showed s p e c i f i c r e s i s t a n c e s t h a t w ere i d e n t i c a l w i t h in e x p e rim e n ta l e r r o r from 1£0° - 160°C. At th e s e te m p e ra ta re s such sam ples a r e known to he i n th e !fo rm of s o a p - b o ile r * s neat* soap and m iddle soap* r e s p e c t i v e l y . ^hus i t a p p e a rs t h a t an a tte m p t to d eterm in e c o n d u c tim e tr i- c a l l y th e b o u n d a rie s of th e tw o-phase r e g io n between them would be u n s u c c e s s f u l. In o rd e r to s tu d y c o n c e n tra te d sodium s t e a r a t e sytems a t low er te m p e ra tu re s , a c e l l w ith e le c t r o d e s of la r g e a re a was d e s ig n e d . The c e l l consi s t e d of a bored m onel-m etal c y l i n d e r , and a t i g h t l y f i t t i n g p lu n g e r. S u i t a b l e i n s u l a t i o n and g a s k e tin g made i t p o s s i b l e to measure r e s i s t a n c e s o f sam ples p laced in th e bore and held i n c o n ta c t w ith th e e le c tr o d e s by p la c in g p r e s s u r e on the p lu n g er by a C arver P r e s s - C onductances were found to be s e n s i t i v e to p re v io u s p r e s s u r e tr e a tm e n t in th e c e l l . P o s s ib le re a so n s f o r t h i s b e h a v io r were d is c u s s e d . At a r b i t r a r y r a t e s o f h e a tin g and a t u n d is tu rb e d p r e s s u r e s , "b re a k s" in th e LPT c u rv e s f o r sam ples o f w a ter c o n te n ts of a few p er c en t or l e s s o c cu rred a t te m p e ra tu re s c lo s e to 5£° smd 71°C, te m p e ra tu re s a t which phase changes for anhydrous and s l i g h t l y hydrous sodium s t e a r a t e have been d e m o n stra te d . The r e s u l t s a r e o f i n t e r e s t w ith r e f e r e n c e to th e a p p a re n t i r r e v e r s i b i l i t y of the change a t 5£°C. BIBLIOGRAPHY - 1 2 0 - BIBLIOGRAPHY 1. R. H F ergu son, F. B. R osevear, and H. N ordsieck, J . Am. Chem. S o c . , 6 £ , 141 (1947)* 2. K. W. G a rd in e r, M. J . B u erg er, and L. B. Smith, ' J . P h y s. Chem., 49, 417 (1945)• 3 . R. D. Void, J . P h y s. Chem., 4£, 3 I 5 (1945). 4. M. H. F i s c h e r , and M. 0 . Hooker, The L y o p h ilic C o l l o i d s . S p r i n g f i e l d , 11 1 .: C harles C. Thomas Pub. Co., 1933 • 5 . S. 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Hovorka and E. E. M endenhall, J . Chem. E d . , 16, 2 3 9 ( 1 9 3 9 ). 1 3 . B. Hague, A l t e r n a t i n g C u rren t B rid ge Methods. London: Is a a c Pitm an and Sons, L t d . , 1938. Page 2 3 8 . 14. B. Hague, A l t e r n a ti n g C u rren t B ridge Methods. London: Is a a c Pitm an and Sons, L t d ., 1938. Pp. 542-551. 1 5 . J . D. Heldman, Techniques o f G lass M a n ip u la tio n in S c i e n t i f i c R e s e a r c h . New York; P r e n t i c e - H a l l , I n c ., 1946. 16. S tu p a k o ff L a b o r a to r i e s , I n c . , C atalo g o f T e c h n ic a l D ata, S e r ie s KA. P i t t s b u r g h , P enn.: StupakoIT L a b o r a t o r i e s , I n c . , lg?4 . Sheet 1. •4121- 17. N. A. Lange, Handbook of C h e m istry . Sandusky, Ohio: Handbook P u b l i s h e r s , I n c ., 1946. Page I 3 8 4 . 18. L. L. Lyon, 4 1 A R h e o lo g ic a l Study o f S o lid Soap System s,*1 U npublished d o c to r a l d i s s e r t a t i o n , th e U n iv e rs ity of S o u th e rn C a l i f o r n i a , Los A ngeles, C a l i f o r n i a , 1944. 1 9 . R. D. Void and M. J . Void, J . Am. Chem. S o c . , 61, 8 0 8 (1939)- 20 J . M. P h i l i p s o n , M. J . Heldman, L. L. Lyon, and R.D.Vold, O il and Soap, 21, 3 I 5 (1 944 ). 21. J . M. P h ilip s o n , ^ P r e p a r a tio n o f Pure Sodium S t e a r a t e , u U npublished 290L r e p o r t , the U n iv e r s ity of S o uthern C a l i f o r n i a , Los A ngeles, C a l i f o r n i a , 1944. 22. J M. P h ilip s o n , #,P r e p a r a tio n o f Pure S t e a r i c A c id ,w U npublished 290 L r e p o r t , th e U n iv e rs ity o f S outhern C a l i f o r n i a , Los A ngeles, C a l i f o r n i a , 1943- 2 3 . M. J . V oid, JV L Macomber, and R. D. Void, J . Am. Chem.Soc. 6 3 , 168 (1 9 4 1 ). ~ 24. R. D. V oid, J . P h y s. Chem. , 49, 3 I 5 (194 5). 2 5 . J . W. 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Ferguson, F. B. R osevear, and R. C. I n d . E ng. Chem. , 3 5 , 1005 (19^3)» f » S t i llm a n , APPENDICES A PPEN D IX 1 A Method for Determining 2 Independently of ■ . ............. V ;....... their Separate Values Any suitable resistor, Rg, was-placed in a direct current bridge whose other aims were R , R_, and R , arranged in such a - -- 1 2 Box way that R R s _ 2 R R (1 ) Box 1 R Box 9 was se^ f°r a balance, aid its value noted* Then 1 R and R were interchanged so that 2 1 R. R, _® = (2) Bt. K Box 2 ..2. . - . . and the value of R- obtained at balance* •Boatj It follows algebraically that APPENDIX 2 Calculations of the Amounts of Water in the Vapor Phases of the "Wire" Conductance CeUs The calculations that follow show the changes in composition of the condensed phase that may occur under extreme conditions* The ideal gas laws and Raoult1 s law are assumed to hold.* Let: o 3 5 80 s vapor pressure of water in atmospheres at 300 C ♦ 55^ inner diameter of the cell in centimeters •35- weight of the sample in grams L « length of the tube not filled by solid v = volume of the vapor phase £ « . partial pressure of water = . mol fraction in condensed phase w s s weight of water in grains left in the condensed phase m m weight of water in grams in the gas phase 18 s = molecular weight of water 306 a molecular weight of sodium stearate n s . - % water in the sample *See footnote, page kl -126- ; Then: w 4 m s. .0035 x n (1 ) w P - IB - 306w neglecting (2) * *35 - (w > m) 306w 4 6.3> 18 4 306 the term (w 4 m) as not affecting p considerably* 4n s PViXffrs . Px 80 x *784 x (*55)2 x 18 x L t nfmPT ; - - - - RT ... ^ ■ - 82 x 573....... . ’ w The three equations above can be solved for m in terms of Land n, thus: m / 3 0 6 w ^ - .0073 1 306W 4 6.3/ “ = *0073 [ f S t L . . (4) The solution for the quadratic equation (4) in "m” is m - l»17n + 6.3 + 2.2UL ± \J(1. 1 7 n + ■ 6.3 + .2.24L)^ -4 x 306 x .00785Ln 2 x 3 0 6 " for which the root arising when the + sign precedes the radic a n d is extraneous« Thus: m - 1.17n 4 6.3 4 2.24 L-m.l7n 4 6.3 < ■ 2.24L)^ - 9*60 Ln (5) 712 When n s 1> L s 1* substituting into (5) gives tf S.Q0072. The composition of the condensed phase is thus . • ■ 022£.-f9P. Q jg x 1 0 0 = o.8jg , instead of the .1*0$ water content originally* - 1 2 7 - When n s 5. L - 1. the solution for (5) is m - .00251» for which the composition of the condensed phase is ^ ^ , . o o2a x l o o n ^ '.' ■ , ........ instead of the 5 % original water content*, In all cases, L was kept under one centimeter. Since no significant results were obtained for any sample of J jL or more water o above 200 C, it is safe to say that for each sample, the composition of the condensed phase did not differ by more than a few tenths of a percent from the composition of the prepared sample. ELECTRICAL CONDUCTIVITIES OF PTOE SOAP-WATER SYSTEMS A D i s s e r t a t i o n P re s e n te d t o th e F a c u lty o f th e G raduate School The U n i v e r s i ty of S o u th ern C a li f o r n ia In P a r t i a l F u lf illm e n t o f th e R equirem ents f o r th e Degree D octor of P h ilo so p h y M orris J* Heldman March 1§47 U M I Number: DP21739 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, th ese will be noted. Also, if material had to be removed, a note will indicate the deletion. Dissertation Publishing UMI D P21739 Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United S tates Code ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, M l 48106 -1.346 j t 41 H *1? o _ This dissertation, written by Morris J, .Heldman under the guidance of A i.8. Faculty Committee on Studies, and approved by all its members, has been presented to and accepted by the Council » on Graduate Study and Research, in partial ful- fillment of requirements for the degree of D O C T O R O F P H I L O S O P H Y " Dean Secretary Date.. June .1947............. Committee on Studies Chairman TABLE OF CONTENTS CHAPTER PACE I INTRODUCTION ........................ ,1 The Problem . . . . . ................................................... 1 S ta te m en t o f the Problem . . . . . . . . 1 Im portance of th e Study . . . . .- . 1 Review of th e L i t e r a t u r e 3 O rg a n is a tio n of th e D i s s e r t a t i o n ......................... 6 I I APPARATUS AND MATERIALS.................................................. 7 A pparatus ............................................................ 7 The W heatstone B r i d g e .................................. . 7 The O s c i l l a t o r and B rid g in g .................... 7 T ransform ers The N u ll- P o in t I n d i c a t o r and i t s In p u t T ransform er ................................... 15 R e s is ta n c e A r m s .................................. 19 S h ie ld in g ........................ 20 O p e r a t i o n ....................................... 21 Accuracy of th e B ridge ......................... 21 C o n d u c tiv ity C ells .................................................. 23 S ealed G lass C e lls .... .. ... 23 P lu n g e r C e ll . 26 Ovens and T h e rm o s ta ttin g A rrangem ents. . 29 The Oven fo r the S ealed G lass C e lls . 29 Thermos t a t t i n g Arrangem ents f o r the Plunger C e l l ....................................................... 30 TABLE OF CONTENTS (C o n tin u e d ) CHAPTER PAGE M a te r ia ls . . . .................... • • • • • • • • 33 Sodi um P a lm ita te . . ........................................ 33 Sodium S t e a r a t e ........................ 33 I I I CONDUCT IVITIES OP ANHYDROUS SODIUM PALMITATE 35 IV CONDUCTIVITIES OP SODIUM STEARATE-WATER SYST.MB OP LOW WATER CONTENT ......................... 40 In S ealed C ells ........................ 40 P r e p a r a t io n of Samples . ........................... . 40 Conductance M e a s u r e m e n t s ............................. 42 Phase I m p lic a tio n s ....................... 67 Frequency Dependence of C o n d u c tiv ity . . 76 I n t e r p r e t a t i o n s of th e C o n d u c tiv itie s . 78 In th e P lu n g e r C e ll ................................... 86 V CONDUCTIVITIES OP THE SODIUM STEAK ATE-WATER SYSTEM IN THE MIDDLE SOAP AND SOAP BOILERS* NEAT SOAP REGIONS ..................................................................103 E x p erim en tal ............................................ 103 R e s u lts above 8 0 ° ............................. 104 Phase I m p lic a tio n s a t Lower T em peratures . 110 SUM M ARY ..................................................... 113 BIBLIOGRAPHY . . .................... ..... CHAPTER TABLE OF CONTENTS i (C ontinued) PAGE APPTH DICES: 123 Appendix 1 . Appendix 2< A method fo r D eterm ining fh e H a tio R^/IL^ In d e p e n d e n tly o f t h e i r S e p a ra te V alues . 124 .C alcu latio n of th e Amounts of W ater i n th e Vapor Phase o f th e "Wire" Conductance C a l l s ........................ 125 LIST OF TABLES TABLE HUMBER PAGE I C a l i b r a t i o n of th e O s c i l l a t o r . . . . . . . 16 I I S p e c if ic R e s is ta n c e s o f Sodium P a l m i t a t e . . 38 I I I I d e n t i f i c a t i o n o f Samples of Sodium S t e a r a t e w ith Low Water C o n t e n t ...............................43 IV S p e c if i c R e s is ta n c e s of Sodium S t e a r a te A • 44 V S p e c if ic R e s is ta n c e s of Sodium S t e a r a t e B • 45 VI S p e c if i c R e s is ta n c e s o f Sodium S t e a r a t e C . 46 V II S p e c if ic R e s is ta n c e s of Sodium S t e a r a t e D , 47 V III S p e c if ic R e s is ta n c e s of Sodium S te a r a te E . 48 IX S p e c if ic R e s is ta n c e s of Sodium S t e a r a te F . 49 X S p e c if ic R e s is ta n c e s of Sodium S t e a r a t e H . 50 XI S p e c if ic R e s is ta n c e s of Sodium S t e a r a t e I . 51 X II S p e c if i c R e s is ta n c e s o f Sodium S t e a r a te J . 52 X III S p e c if ic R e s is ta n c e s of Sodium S te a r a te K . 53 XIV C o n d u c tim atric Changes O ccu rrin g in . Sodium S t e a r a t e Systems of Low Water C ontent ........................ 68 XV Frequency Dependence of C o n d u c tiv ity of Sodium S te a ra te -W a te r Samples . . . . . . . 77 XVI R e s is ta n c e s of Sodium S t e a r a t e 0 . . . . . 92 XVII R e s is ta n c e s o f Sodium S t e a r a t e P . . . . . 93 XVIII R e s i s t a n c e s of Sodium S t e a r a t e Q ............................94 XIX R e s is ta n c e s of Sodium S t e a r a t e B ........................... 95 XX R e s is ta n c e s of Sodium S t e a r a t e S ............................96 LIST OF TABLES (Continued) TABLE MJMBER PACE * XXI R e s is ta n c e s of Sodium S t e a r a t e £ • « • • • 97 XXII R e s is ta n c e s of Sodium S t e a r a te U .................98 XXIII R e s i s t a n c e s of Sodium S t e a r a t e V • . . . . 99 XXIY R e s is ta n c e s of Sodium S t e a r a t e W ..............100 XXV Summary of C o n d u c tim etrie R e s u lts w ith Sodium S te a ra te -W a te r Systems i n P lun ger C e l l s ................................................................................101 XXVI S p e c ific R e s is ta n c e s o f Sodium S t e a r a t e M 105 XXVII S p e c ific R e s is ta n c e s of Sodium S t e a r a t e H 106 LIST OF FIGURES FIGURE HUMBER PAGE I Schematic Diagram of th e Bridge C i r c u i t . . • . ........................ 8 I I Schem atic C i r c u i t of th e O s c i l l a t o r and B rid g in g T r a n s f o r m e r s ............................ . 10 I I I Schem atic C ir c u it of the N ull P o in t I n d i c a t o r ...................................................................... 17 IV The P lu n g e r C e l l .................................................. 28 V S p e c i f i c R e s is ta n c e s of Sodium P a l m i t a t e ..................................................................... 39 VI S p e c if i c R e s is ta n c e s of Sodium S t e a r a t e A ........................................................... . 54 V II S p e c if ic R e s is ta n c e s of Sodium S t e a r a t e B ............................. 55 V III . S p e c if i c R e s is ta n c e s of Sodium S t e a r a t e C .................................. 56 IX S p e c if i c R e s is ta n c e s of Sodium S t e a r a t e D . . . . . . . . . . . . . . 57 X S p e c if ic R e s is ta n c e s of Sodium S t e a r a t e E .................................................. 58 XI S p e c if ic R e s i s t a n c e s o f Sodium S t e a r a t e P ........................ 59 X II S p e c i f i c R e s is ta n c e s of Sodium S t e a r s t e H . . . • . . . . . . • • * . 60 X III S p e c if ic R e s is ta n c e s of Sodium S t e a r a te I . . . . . . . . . . . . . . 61 XIV S p e c i f i c R e s is ta n c e s of Sodium S t e a ra t e J . . . . . . . . . . . . . . 62 XV S p e c if ic R e s is ta n c e s of Sodium S t e a r a t e K . . . . . . . . . . . . . . 63 LIST OF FIGURES (Continued) FIGURE NUMBER PAGE XVI Phase Diagram o f Sodium S te a ra te -W a te r . ............................................... 69 XVII S p e c i f i c R e s is ta n c e s of Sodium S t e a r a t e M ..................................................... . 107 XVIII S p e c if i c R e s is ta n c e s of Sodium S t e a r a t e U ................................................................ 108 The a s s i s t a n c e of D r. B o b e rt D. Told i s g r a t e f u l l y acknowledged. CHAPTER I INTRODUCTION A. The Problem S ta te m en t o f th e Problem , I t was th e purpose o f t h i s i n v e s t i g a t i o n (1) to m easure a l t e r n a t i n g - c u r r e n t conductances o f c o n c e n tra te d soap system s as fu n c tio n s of co m p o sitio n s, te m p e r a tu r e s , and f r e q u e n c ie s , as w e ll as h i s t o r i e s o f te m p e ra tu re and p r e s s u r e ; (2) to i n t e r p r e t such f in d in g s i n term s o f th e b o u n d a rie s and n a t u r e of th e p h ases p r e s e n t i n th e system s i n v e s t i g a t e d , as w e ll as in term s o f th e n a tu r e o f th e co n d u ctan c es; (3) to c o r r e l a t e t h e s e r e s u l t s w ith th o s e o b ta in e d by o th e r e x p e rim e n ta l m ethods. Im portance o f th e S tu d y . The com plete e l u c id a t io n o f a phase diagram f o r th e b in a r y system o f so a p -w a te r has n o t been e f f e c t e d as y e t f o r any so ap . One of th e te m p e ra tu re -c o m p o s itio n a re a s which i s th e s u b je c t of a l i v e l y c o n tro v e rs y a t p r e s e n t i s th e one below a b o u t 100°C, and e x te n d in g over p r a c t i c a l l y th e e n t i r e co m p o sitio n 1 , 2 , 3 . ra n g e . P a r t i c u l a r l y i n th e c o n c e n tra te d - s o a p a re a such a diagram would be q u i te im p o rta n t p r a c t i c a l l y , f o r i t would r e p r e s e n t th e changes which occur i n th e s o a p - k e t t l e upon c o o lin g or d ry in g , a s w e ll as th e c o n d itio n of soap i n i t s s to r a g e and u s e . A nother r e g io n which has been d i f f i c u l t to s tu d y i s th e one above 100°0 and w i t h l e s s th a n about 10$ w a te r . -2- F i n a l l y t h e r e a r e s e v e r a l narrow two phase re g io n s around th e c e n t e r o f th e b in a ry diagram s; t h e . p o s i t i o n s of th e b o u n d a rie s of th e s e re g io n s a r e b u t p o o rly d e fin e d from e x i s t i n g d a ta . P re lim in a ry c o n s i d e r a ti o n s and some ex p erim e n ts had i n d i c a t e d t h a t c e r t a i n p a r t s of the r e g io n s d is c u s s e d above c o u ld be s t u d i e d e o n d u c t im e tr i c a l ly . Thus i t was f e l t t h a t such a s tu d y would be a c o n t r i b u t i o n to th e knowledge o f th e phase p r o p e r t i e s of t h e t h e o r e t i c a l l y and p r a c t i c a l l y i n t e r e s t i n g so a p -w a te r system s* The d a ta o b ta in e d sho uld a ls o be u s e f u l in e s t a b l i s h i n g a mechanism or mechanisms f o r conductance i n t h e s e system s, and th u s perh aps a i d in e x p la in in g some of th e p e rp le x in g problem s e n c o u n te re d , such as th e r a t e o f o r i e n t a t i o n and g ro u p in g o f m o le c u le s, th e d i s t r i b u t i o n of w a te r , and th e changes o c c u rrin g in th e s e p r o p e r t i e s a s a f u n c tio n of te m p e ra tu re and o th e r v a r i a b l e s . - 3 - B . R e v ie w o f t h e L it e r a t a r e Although t h e r e a r e l i t e r a l l y hundreds of p u b lis h e d i n v e s t i g a t i o n s on t h e c o n d u c tiv e trig..: b e h a v io r o f d i l u t e system s of soaps i n w a t e r , * a s e a r c h of the l i t e r a t u r e r e v e a ls only two s e t s o f a c c o u n ts o f such s t u d i e s on more c o n c e n tr a te d 4 ,5 sy ste m s. In t h e f i r s t a c c o u n t, M. H. I*iseher and M. 0 . 4 Hooker a tte m p t to e x p la in th e tem perat u re-c o n d u cta n ee b e h a v io r o f some c o n c e n tr a te d system s o f soap in w a te r , w ith th e main em phasis on the developm ent o f th e " s o l u b i l i t y " h y p o th e s is a s a g e n e r a l th e o ry a p p lic a b le t o l y o p h i l i c 6 c o l l o i d a l system s* The fo llo w in g s ta te m e n t by Hartman summarizes what is meant by t h e t h e o r y . . • .The e f f e c t o f tem p era tu re on a 25 p e r c en t m ix tu re o f p otassium pa I m i t a t e (o r any l i g h t m etal soap) and w a te r or a lc o h o l (or o th e r s o l v e n ts ) i s d e s c rib e d as fo llo w s . Between th e te m p e ra tu re s o f 100° and 85°C the soap i s c o n s id e re d to be d is s o lv e d in th e s o l v e n t , y i e l d i n g a t r u e homogeneous s o l u t i o n i n vshich t h e soap m olecu les a r e d is p e r s e d i n the s o lv e n t and in which a c o n d itio n o f d i s c r e t e d i s c o n t i n u i t i e s e x i s t . . . . As th e te m p e r a tu re i s d e c re a s e d , • • . • the soap becomes p r o g r e s s i v e l y l e s s s o lu b le in th e s o l v e n t , w ith th e consequence t h a t t h e p a r t i c l e s o f soap g r a d u a lly assume * The two m ost prom inent l e a d e r s of groups i n v e s t i g a t i n g in t h i s f i e l d a r e J . W. MeBain and G. S. H a r tl e y . dim ensions g r e a t e r th a n th o s e o f soap m o lecu les . . . . As the te m p e ra tu re i s d e c re a s e d . . . . , the i n t e r n a l - p h a s e p a r t i c l e s a re th o u g h t t o he so la r g e t h a t th ey tou ch one a n o th e r and f i n a l l y c o a l e s c e . C on sequen tly the e x te r n a l phase becomes th e i n t e r n a l p h a s e ." The f a c t t h a t t h e r e a re sharp- " b re a k s ” i n th e c o u rs e s o f the t e m p e r a t u r e - r e s i s ta n c e cu rv es o f v a rio u s c o n c e n tr a te d s o a p -w a te r system s i s c i t e d as ev idence t h a t such systems " i n v e r t 1 1 from l y o p h i l i c ones o f soap d is p e r s e d i n w a te r t o ly oph obic ones of w a te r d is p e r s e d in soap a s the te m p e ra tu re is low ered, and v i c e - v e r s a . Many o t h e r sy ste m s, such as q u in o lin e /w a te r , p h e n o l/w a te r, g e l a t i n / w a t e r , and heavy m etal s o a p s /s o lv e n ts show a s i m i l a r b e h a v io r . The l a r g e amount o f evid en ce i n fa v o r of a " b ru sh - 7 heap" s t r u c t u r e f o r c o n c e n tr a te d so a p -w a te r system s makes the th e o ry o u t li n e d above u n te n a b le . A lso, no sy s te m a tic a tte m p t was made to s tu d y th e " i n v e r s i o n ” te m p e ra tu re s as f u n c tio n s of com positions o r p re v io u s h i s t o r i e s , n o r was the method o f o b t a i n i n g c o n ta c t betw een th e samples and th e e l e c t r o d e s proveid t o be a d e q u a te . Thus i t is d i f f i c u l t to se e how M. H. F i s c h e r 's work can s e rv e a s more th an an o r i e n t a t i o n f o r f u t u r e w orkers in th e f i e l d . The second c o n d u c tim e tric stu d y of c o n c e n tra te d so a p -w a te r system s i s even more in a d e q u a te in sc o p e, v a l i d i t y , 5 and la c k of d e s c r i p t i o n of e x p e rim e n ta l te c h n iq u e s . 5 S. S. B hatnagar and M. P ra sa d s t u d i e d th e c o n d u c t i v i t i e s of s e v e r a l "m olten" sodium and p o tassiu m soaps from 182°G to 207°C on b o th a l t e r n a t i n g and d i r e c t c u r r e n t b r id g e s . The soaps w ere made by n e u t r a l i z i n g f a t t y a c id s o f u n s ta te d o r i g i n , and w ere d r i e d in a n oven a t 40°C, and th e n f o r a week i n a d e s i c c a t e r over calcium c h l o r i d e . B e s is ta n c e m easurem ents w ere f i n a l l y made on sam ples p la c e d in sm a ll b e a k e rs w ith g o l d e l e c t r o d e s . The r e s u l t s can be c r i t i c i z e d on th e fo llo w in g grounds: ( l ) The p u r i t y o f th e f a t t y a c i d s and th e r e s u l t i n g so ap s is u n c e r t a i n , e s p e c i a l l y s in c e S. S. B h a ta ag a r and M. P ra sa d c la im th e y n e u t r a l i z e d the acids:‘in a lc o h o l s o lu t i o n to b o th p h e n o lp h th a le in and litm u s I (2C ), P ry in g soaps under th e c o n d itio n s s t a t e d does not make them anhydrous, a c c o rd in g to th e p r e s e n t w r i t e r ' s e x p e rie n c e . The very marked dependence of th e c o n d u c t iv i t y of such systems on the w a te r c o n te n t (C hapter IY) s e r v e s in i t s e l f to i n v a l i d a te alm ost c o m p le te ly a l l o f th e r e s u l t s o b ta in e d by S. S. B h atnagar and M. P r a s a d . (3) N e ith e r th e ty p e o f e l e c t r o d e s , n o r the method o f o b t a i n i n g c o n ta c t , i f any, was d is c u s s e d . (4) H eating samples to th e te m p e ra tu re s a t which m easure ments w ere made (182° to 207°) i n a n open b e ak e r c e r t a i n l y r e s u l t e d in changes o f c o m p o sitio n , s c o r c h in g , o r b o th . Thus i t can be seen t h a t th e p u b lis h e d c o n d u c tim e tric in fo rm a tio n on c o n c e n tr a te d so a p -w a te r system s is q u i te meager, and t h a t what does exiw t i s d is c o n n e c te d and in some c ases not v a l i d . - 6 - 0» O r g a n iz a t io n o f t h e D i s s e r t a t i o n F o llo w in g th e p r e s e n t i n t r o d u c t o r y c h a p te r , the a p p a r a tu s and m a t e r i a l s used in th e i n v e s t i g a t i o n a re d e s c rib e d a t some le n g th in C hapter I I . The t h i r d c h a p te r c o n s id e r s th e c o n d u c t i v i t i e s o f anhydrous sodium p a l m i t a t e , and i s fo llo w ed by two c h a p te r s about c o n d u c t i v i t i e s of sodium s t e a r a t e - w a t e r sy ste m s. The f i r s t o f th e s e concerns i t s e l f w ith system s of low w a te r c o n te n t s t u d i e d by means o f two d i f f e r e n t ty p e s of c o n d u c tiv ity c e l l s , and r e p r e s e n ts th e major p o r t i o n o f th e problem a s f a r a s b o th e f f o r t s and f in d in g s a r e concerned. The o th e r c h a p te r of s t u d i e s on s o d iu m - s te a r a te w ater system s compares th e c o n d u c t i v i t i e s o f so ap b o i l e r fs n e a t soap and m iddle soap , phases n o t found a t th e low w a te r c o n c e n tr a tio n s i n v e s t i g a t e d i n th e p re v io u s c h a p t e r . A summary and b ib lio g r a p h y - C hapters VI and V II - fo llo w , and th e r e p o r t i s concluded w ith two a p p e n d ic e s. - 7 - CHAPTER I I APPARATUS A W D MATERIALS A. A pparatus M easurements o f conductance w ere made w ith an a l t e r n a t i n g - c u r r e n t W heatstone B ridge* T his b r id g e , diagrammed s c h e m a tic a lly in F ig u re I , a s w e l l as the c o n d u ct i v i t y c e l l s and th e ovens used t o v a ry th e te m p e ra tu re of th e sam p les, a re d e s c rib e d i n d e t a i l b elo w . 1. The W heatstone Bridge The o s c i l l a t o r and b r id g in g t r a n s f o r m e r s : The source of v o l ta g e f o r th e b r i d g e was a c o n ti n u o u s l y - v a r i a h le a u d io fre q u e n c y o s c i l l a t o r . S ince c o n d u c t i v i t i e s may be dependent upon the freq u e n cy a t which they a r e m easured,, i t was d e s i r a b l e to have a so u rc e o f a l t e r n a t i n g p o t e n t i a l s o f v a r i a b l e freq u e n cy and. p u re sine-w ave form . The in stru m e n t t h a t was f i n a l l y c o n s tr u c te d met th e s e re q u ire m e n ts s a t i s f a c t o r i l y . F re q u e n c ie s which v a r i e d c o n tin u o u s ly from abo ut 20 t o 20,000 c y c le s w ere a v a i l a b l e ; th e wave form a t a l l fre q u e n c ie s showed no n o t ic e a b l e d e p a rtu re from t h e sine-w ave form on a 5" c a th o d e - r a y o s c i ll o s c o p e . Such an in stru m e n t i s e a s i l y c a p a b le of showing a s l i t t l e as 5% d i s t o r t i o n . The m agnitude of th e o u tp u t v o lta g e was about 20 v o l t s in to a h ig h impedence lo a d in the m iddle range o f f r e q u e n c i e s , w ith a s l i g h t drop a t both ends of th e a v a i l a b l e spectrum . About 1 volt; o u tp u t was a v a i la b l e i n t o a low (10 ohm) M S M S ^ O O O 'O S s/WWWWV r u a ^ o O O O 'O S AWAAMr S ' - ' I O O O O S vAA AA/W vV frt/on o f C om ponents on n e * t fr&y'e) -v.r v,r M /V W ^ s9 o ' - •^ A A A A f" C fe r -© S A A /W — o o« < v > 10 _ 3 c © i c O f o 4 ; £ * 0 . V /> < 0 X o rmryw I- K S M - 1 1 - PI GURE I I (Continued) SCHEMATIC CIRCUIT OP THE OSCILLATOR AND BRIDGING TRANSPORMERS 0, - 4-gang 365 mmfd. 1 b . c . condenser Cg - .000075-mfd* m idget mica C , C - l.O -m fd. 4 0 0 - v o lt ® x u b u lar V V V V c9 - 8 mfa- 4 5 0 -v o lt e l e c t r o l y t i c t a b u l a r °10* ° n “ 16~mfd* 450- v o l t e l e c t r o l y t i c R_ , R r - - 10 megohms, l / 2 1 '5 w a tt R , R - 1 .25 megohms, l / 2 2 6 watt (1 megohm and 250,000 ohms i n s e r i e s ) Bg , B - 150,000 ohms, 1/2 w a tt B4 , Bo - SO,000 ohms, 1/2 w a tt Rn , - 1,800 ohms, 1 w a t t y RlO - 500,000 ohms, l / 2 w a tt R1n - 100,000 ohms, l / 2 • L1 w a tt R_ - 500,000 ohms, 1/2 w a tt - 100,000 ohms, l / 2 w a tt ^14 ~ °*ims * w a tts ^15 ~ &0i00Q ohms, 1 w att'. R_. - 50,000 ohms, 1 w a tt 16 R1y - 10,000 ohms*, 10 w a tts R l8 - 25,000 ohms* 10 w a tts R ^ 9 * * SOO ohms* 10 w a t ts RLX, RLg - 6 w a tt 1 2 0 -v o lt tu n g s te n mazda lamp T-. - 580 c . t . , -50 raa.; 5 v . 3 a . ; 6 .3 v .2 a . OH - 10 - hy. 65 - ma. f i l t e r choke S , Sg - 2 -p o le 6 - p o s i t i o n s w itc h (o n ly 4 p o s i t i o n s used) 3* - S . p . s . t * a . c . 3 l i n e s w itc h 3, - S . p . d . t . sw itc h 4 T - H adley #7562 2 - H adley #7558 - 1 2 - s t e e l c h a s s i s . The power su p p ly was on one end o f th e c h a s s i s (ab out a 4 ” p o r t i o n ) , and was s h ie ld e d b o t h above and below by s h e e t m etal s t r i p s run nin g a c ro s s th e w id th of th e c h a s s i s . The to p s h i e ld ex te n d ed up abou t 5W , and was a t t a c h e d to th e f r o n t p anel of th e s t e e l box by b o l t s . The low er s h i e l d was b o l t e d to th e f r o n t and back o f t h e c h a s s i s . The s h i e l d i n g was n e c e s s a r y to i s o l a t e from th e power su p p ly , s in c e th e fo rm e r was a t g rid p o t e n t i a l and h ig h impedance, and th u s o th erw ise would have ten d e d to p ic k up th e l i n e fre q u e n c y . F or the same r e a s o n , t h e o s c i l l a t o r was always o p e ra te d w ith th e box c lo s e d . C-^ was i s o l a t e d from th e c h a s s i s b y i t s b e in g mounted on 3 p o r c e l a i n l e a d - i n b u sh in g s (Johnson # 5 1 ), w ith h a l f of each b u sh in g on e i t h e r sid e o f th e c h a s s i s , ^he tu n in g con denser s h a f t was coupled th ro u g h a m ethyl m e th a c r y la te (L u c ite ) r e s i n i s o l a t i n g c o u p le r to a n o th e r s h a f t w hich p assed th ro u g h th e f r o n t p a n e l . A p o i n t e r knob was mounted on th e l a t t e r s h a f t over a 1-100 d i a l b o l t e d to th e f r o n t p a n e l . £11 o th e r c o n t r o l s , in c lu d in g th e ja c k s fo r th e v a r io u s ou tp u t impedance^ came out to th e f r o n t p a n e l . 1° B:. Hague shows t h a t an A.C. b rid g e h a s maximum s e n s i t i v i t y when th e impedances of each of th e fo u r arms as w e ll as t h a t o f th e in p u t and th e b a la n c e c i r c u i t ( t h a t i s , a c r o s s th e n u l l - p o i n t i n d i c a t o r ) a r e e q u a l . I t i s custom ary t o employ b r i d g in g tra n s fo rm e rs a c r o s s th e o u tp u t f o r impedance m atch in g . An a d d i t i o n a l d e s i r a b l e f e a t u r e of such - 1 3 - tr a n s f o r m e r s i s t h a t th e y i s o l a t e t h e o s c i l l a t o r c h a s s i s from th e b r id g e c i r c u i t proper# Two o u tp u t tr a n s fo r m e rs (Hadley #7558 and #7562) were mounted on th e o s c i l l a t o r c h a s s i s , The #7558 was c o n n e c te d a s a step-down tra n s fo r m e r, and th e #7562 as a s te p - u p ; e i t h e r tr a n s f o r m e r was c ap a b le of b e in g p la c e d i n th e cathod e c i r c u i t of th e o utp ut tu b e by means of S^. The prim ary of each tr a n s fo r m e r had a d i r e c t - c u r r e n t r e s i s t a n c e o f a b o u t 600 ohms# In p r a c t i c e i t was found t h a t th e b rid g e was s u f f i c i e n t l y s e n s i t i v e so th a t th e in p u t impedance was n o t very c r i t i c a l # B e s is ta n c e s of a b o u t 1000 ohms o r more w ere g e n e r a l l y m easured u sin g a tap of the #7562, and th o s e o f l e s s th a n t h i s f i g u r e w ith one of th e ta p s o f th e #7558. C was n e c e s s a ry to m a in ta in a c a p a c i t y b a la n c e betw een th e two s e c t i o n s o f co ndenser C^# The low er s e c t i o n had a much g r e a t e r c a p a c i t y to ground, so th e trim m ers on t h a t s e c t i o n were tu rn e d a l l t h e way o u t, and th e n th e trim m ers i n p a r a l l e l w ith Cg w ere v a r i e d u n t i l smooth o s c i l l a t i o n was m a in ta in e d over a l l bands# This was o bserved w ith a c a th o d e -ra y o s c i ll o s c o p e ; the a d ju stm e n t was most c r i t i c a l around th e low fre q u e n cy range# Once s e t , th e trim m ers were n o t changed. B was r a t h e r c r i t i c a l # The lo w e st v a lu e t h a t co u ld y he used w ith o u t th e appearance o f d i s t o r t i o n in th e o utput wave was t h e v a lu e shown, namely 1,800 ohms. An 84/6Z4 r e c t i f i e r tu b e was used b e c a u se o f i t s low f ila m e n t c u r r e n t ; th e 5Y3GT tube f i r s t t r i e d produced too much h e at and su b sequ ent - 1 4 - changes of^ v a lu e of th e c r i t i c a l c i r c u i t components. Even w ith th e 84/6Z4 t h e s e t d r i f t e d somdwhat in fre q u e n c y d u rin g th e f i r s t o n e - h a lf hour of o p e r a tio n . A f te r t h i s tim e th e fre q u e n c y rem ained c o n s ta n t w ith in the l i m i t s o f m easurement, which was e s tim a te d to be abo ut 1% from th e degree of r e p r o d u c i b i l i t y o b ta in e d i n th e c a l i b r a t i o n s d e s c rib e d below . The fre q u e n c y o u tp u t o f such an o s c i l l a t o r sh o u ld be l/ETTHC, b u t s in c e th e v a rio u s r e s i s t o r s used were n ot c a l i b r a t e d , and s in c e C in c lu d e s any s t r a y c a p a c i t i e s , c a l i b r a t i o n was n e c e s s a r y . This was perform ed a g a i n s t a G en eral Badio Audio Frequency M eter, Type 434-B, S e r i a l #110, found to b e a c c u r a te a g a i n s t th e l i n e fre q u e n c y o f 60 cycles* The method of c a l i b r a t i o n f o llo w s . The o s c i l l a t o r was f e d i n t o t h e in p u t o f the Meter ' and v a rio u s r e s i s t i v e l o a d s , w ith the o u tp u t of th e Meter f e e d in g in to the v e r t i c a l p l a t e s o f a 5n o s c i l l o s c o p e . Bo h o r i z o n t a l g a in of th e o s c i l l o s c o p e was employed, and th u s th e p a t t e r n o b ta in e d was a v e r t i c a l l i n e . The M eter was th e n a d ju s te d f o r minimum o u tp u t, and th e freq u e n cy read as t h a t o f th e o s c i l l a t o r a t t h a t p a r t i c u l a r s e t t i n g . From tim e t o tim e checks were m ade'as to t h e p u r i t y o f th e wave-form and d r i f t i n fre q u e n c y . The r e s u l t s o b ta in e d were s a t i s f a c t o r y , as d e s c rib e d in th e b e g in n in g of t h i s s e c t i o n . When the e x t e r n a l lo a d of th e o s c i l l a t o r was v a r i e d , th e wave-form rem ained u n d i s t o r t e d down t o 2,000 ohms a c r o s s th e hig h impedance c i r c u i t , and 10 ohms a c r o s s th e low impedance c i r c u i t . - 1 5 - There was, however, an e x p ected drop in v o lta g e o u tp u t under the: lo w er l o a d s . The c a l i b r a t i o n curves o b ta in e d were su b s e q u e n tly used i n th e c o n d u c tim e tric work to c o n v e rt d i a l re a d in g s to f r e q u e n c i e s . The d a ta from w hich t h e s e curves were o b ta in e d a re l i s t e d i n Table I . D uring th e c o n s t r u c t io n of t h i s o s c i l l a t o r i t became e v id e n t t h a t w ith c e r t a i n s i m p l i f i c a t i o n s i t could be m o d ified t o be s m a ll, in e x p e n s iv e , and a d a p ta b le t o r o u tin e work, b u t s t i l l r e t a i n i t s s u p e r i o r i t y over o th e r ty p e s . These s i m p l i f i c a t i o n s r e s u l t e d in th e development o f an 01 o s c i l l a t o r now d e s c r ib e d in th e l i t e r a t u r e . The n u l l - p o i n t i n d i c a t o r and i t s in p u t t r a n s f o r m e r : S ince a v e ry l a r g e number of’ m easurements were to be made, i t was d e cid ed to use a v i s u a l n u l l - p o i n t i n d i c a t o r r a t h e r th an th e u s u a l clumsy headphones. The in s tru m e n t f i n a l l y developed ha‘d th e fo llo w in g d e s i r a b l e c h a r a c t e r i s t i c s : f 1) I t was re a s o n a b le i n s i z e , bein g mounted on an 8" x 4 ” m e ta l c h a s s is 2" h ig h and c ov ered w ith a bottom p l a t e . (2) I t needed b u t few a d ju s tm e n ts i n u s e . (3) I t was n o t s e n s i t i v e t o s t r a y f i e l d s . (4) I t was powered from 110 v o l t s A.C. ■ (5) It* o p e ra te d over th e com plete u s e f u l ran g e of th e o s c i l l a t o r d e s c r ib e d . (6) I t was more s e n s i t i v e th an e arp h o n es. If2,13 Such e l e c t r o n i c i n d i c a t o r s have been used p r e v io u s ly . W ith th e se as a s t a r t i n g p o i n t , th e in stru m e n t s c h e m a tic a lly diagrammed i n F ig u re I I I was d evelo p ed . A d e s c r i p t i o n f o llo w s . The power su p p ly was th e u s u a l r a d io ty pe w ith ▼ - 1 6 - TABLE I CA1IBBATI0B OF THE QSCILLATOB D ia l Frequency - O ycles/Second S e t t i n g Bange 1 Bange 2 Bange 3 Bange - 0 below 19 163 1295 "~T$3 O ' 10 20 . 7 1 9 1 .5 1520 9^L50 BO 24.9 222.5 1825 11,050 SO 29.8 274 2275 13,500 40 3 6.4 33T 2800 16,650 50 44.1 415 3480 22,000 60 53.6 518 4370 — 70 66.2 655 5520 — 80 82.6 839 7120 — 90 103.5 1085 9280 - - 100 1 19.2 1250 1Q800 — o r 5 , ■ T o h eatery 6 3 voI t s iieV, '"N o n> n o * o 3 o Tr o 3 n 3 't 0 3 3 ro X r f T r & » - o ft — £ X 9 . o 9 3 -H 4 > r+ ^ 3- A n > O V C n 0 > 0 » - © c " I 0 i • * h i I FIGURE I I I (Continued) SCHEMATIC CIRCUIT OF THE HTJLL-POIHT INDICATOR - 1 7 a - C-,, Cn , C - 8 mfd, 4 5 0 - -L 2 6 v o l t e l e c t r o l y t i c C3# Cgf C - 10 mfd, 25- v o l t e l e c t r o l y t i c CA, Cq , - *03 mfd, p ap er tu b u la r C , C - *1 mfd, paper 7 9 t u b u la r ClO - ,05 mfd, p a p e r t u b u la r - 35,000 ohms, 10 w a tts b2, a10. b 1]l - 500,000 ohms, 1 / 2 w a tt f? - 150*000 ohms, l / 2 w a tt ^ 7 ~ ohms, l / 2 w a tt Hg - 40,000 ohms, l / 2 w a tt Bg - 1 0 0 , 0 0 0 ohms, 1 / 2 w a tt it. 2 - 50,000 ohms volume c o n tr o l T-, - 580 c , t . , 50 ma; 5 v , 3 a , ; 6 ,3v. 2 a , Tg - Thermador # 1 -3 1 CE, - 20 h e n r i e s , 50 ma. v i l t e r chokes S i - S . p . s * t , a . c . to g g le sw itch c o ndenser i n p u t , and fu r n is h e d ah out 240 v o l t s a t th e ju n c tio n o f C 3 E L and C • Any s ig n a l a p p e a rin g a c ro s s th e p rim a ry o f Tg was a m p lif ie d i n cascade by th e two 6SJ7GrT tu b e s , and th e a m p lifie d s i g n a l fe d to t h e g r id of the 6E5 " e l e c t r i c e y e1 1 tu b e . At most f r e q u e n c ie s and r e c t i f i e d th e s i g n a l s u f f i c i e n t l y so t h a t the eye c lo s e d s t e a d i l y w ith an in p u t s i g n a l; i f th e freq uency f e l l much below 100 cycles- the f i l t e r i n g a c t i o n o f t h i s sim ple r e c t i f y i n g c i r c u i t was found to i n s r f f i c i e n t , and th e c lo s e d p o r t i o n of th e eye wavered* Ho f r e q u e n c ie s t h i s low were used i n t h e i n v e s t i g a t i o n ; however, t h i s d i f f i c u l t y cou ld have been e lim in a te d i f n e c e s s a ry by d e sig n in g a more e f f i c i e n t r e c t i f y i n g c i r c u i t . T h e ,in p u t tr a n s fo r m e r, T^, was a Thermador #1-31, w ith two p r i m a r i e s to match 100 or 10,000 ohms, and a high impedance se c o n d a ry . One sid e of th e in p u t was conn ected to te r m in a ls 2, 3, and 4 a s shown, and th e o th e r sid e could be connected to 1, 5 or 6 by t h e use of jacks and a p lu g . These c o n n e c tio n s gave low, medium, and h ig h impedance in p u ts r e s p e c t i v e l y . In use th e g a in of th e a m p l i f i e r was s e t b y Bg, and th e n a rough minimum o b ta in e d by a d j u s t i n g th e r e s i s t a n c e bo x es. Then was s e t so t h a t th e eye alm ost c lo s e d ; a t t h i s p o s i t i o n sm ali changes in th e shadow were e a s i e r to d e t e c t . Thus a more p r e c i s e s e t t i n g of th e r e s i s t a n c e boxes was made p o s s i b l e . S e v e ra l a l t e r n a t e a d ju s tm e n ts o f Bg and B - 1 9 - were o f te n n e c e ssa ry * a s w e l l a s grounding a d ju s tm e n ts to be d e s c r ib e d in a l a t e r s e c t i o n . R e s is ta n c e a rm s: In th e schem atic diagram of th e b rid g e (F ig u re I ) , and would u s u a lly be one e o n tin u o u s ly - v a r i a b l e s l i d e - w i r e . Che n e c e s s i t y f o r approxim ate impedance- 10 m atching of th e b r i d g e arms and th e la r g e ra n g e o f r e s i s t a n c e s en co u n tere d i n t h i s stu d y made i t d e s i r a b l e to make p ro v is io n s f o r v a ry in g R]_ and R s e p a r a t e l y , T his was accom plished by making i t p o s s ib l e to choose 500, 5000, or 50,000 ohms a s each o f th e s e arms, a s shown by F ig u re I . N o n -in d u ctiv e p r e c i s i o n wire-w ound r e s i s t o r s w ere not a v a i l a b l e f o r t h e stu d y , so one c© rb on w a t t / r e s i s t o r s were ch o sen f o r th e s e arm s. Since t h e r e s i s t a n c e of th e c e l l , R , was e q u a l to ^ o x x R g/ th e a b s o lu te v a lu e s 3 C o f Rg and R-^ were n o t im p o r ta n t, T h e ir r a t i or.was determ ined f r e q u e n t l y because th e r e s i s t a n c e s of c arb o n u n i t s a r e known to d r i f t w ith time* However, the d r i f t was found to be not over a few p e rc e n t over a p e rio d of more th an a y e a r . Appendix 1 d e s c rib e s th e method f o r d e te rm in in g th e rsffcio. The t h i r d arm of th e b r id g e , B_ , c o n s i s t e d of a box Leeds and N orthrup 9999 ohm 4 -decade r e s i s t a n c e box* in s e r i e s w ith a 2 -d ecad e 990,000 ohm box. The fo rm er was checked a g a i n s t a Bureau o f S ta n d a rd s 10,000 ohm r e s i s t o r and found a c c u r a te w i t h in th e l i m i t s of th e b r i d g e . One • • • • ♦ ♦ • • • • • • • • ♦ • • ♦ • • • • • • • • • • I * * * *This r e s i s t a n c e box i s l i s t e d as #4775 i n th e Leeds and N orthrup C a ta lo g . The l i m i t s o f th e v a lu e s of th e r e s i s t a n c e s a re s t a t e d a s± 0 .1 $ . -20- decade of th e l a t t e r c o n s i s t e d of 9 n o n -in d u c tiv e * 10 w a t t, ± 1 $ , 1 0,00 0 ohm r e s i s t o r s , m anufactured b y I n t e r n a t i o n a l B e s is ta n c e Company* These u n i t s w ere n o t f u r t h e r c a l i b r a t e d . The second d e cid e o f 100,000 ohm u n i t s was made from 18 i n d u c t i v e , 10 w a t t , ±10$* 50,000 ohm r e s i s t o r s . Each 50.000 ohm r e s i s t o r was c a l i b r a t e d a g a i n s t known r e s i s t o r s on a d i r e c t - c u r r e n t b r i d g e , and p a i r s chosen so t h a t t h e i r s e r i e s - r e s i s t a n c e d id n o t d i f f e r by more th a n a few p e r c e n t from 100,000 ohms. The 990,000 ohm u n it was assem bled i n a 9" x 6" x2" wooden box, the r e s i s t o r s b e in g w ired i n th e custom ary f a s h io n t o th e te r m in a ls o f a p a i r of 1 1 - p o s i t io n s in g le - th r o w s h o r t i n g sw itc h e s (1 p o s i t i o n unused) and to e x te r n a l b in d in g p o s t s . S h i e l d i n g : I t i s w e l l known t h a t a l t e r n a t i n g - c u r r e n t b rid g e s a r e s u s c e p t i b l e to s t r a y f ie ld s * Invo lved s h i e l d i n g and guard c i r c u i t s a re u s u a lly n e c e s s a r y i n measurements of in d u c ta n c e and c a p a c i t y , b ut e x p e rie n c e has shown t h a t a Wagner S h ie ld , c o n s i s t i n g o f a p o te n tio m e te r a c r o s s th e o s c i l l a t o r , w ith th e movah-le c o n ta c t grouded, i s o f te n e f f e c t iv e i n m inim izing such f i e l d s so t h a t r e s i s t a n c e measurements 14 can be made. By t r i a l and e r r o r i t was found t h a t such a s h i e l d was u n n e c e ssa ry when each of the arms was below abo u t 10.000 ohms, t h a t e f f e c t i v e s h i e l d i n g was p o s s i b l e u sin g a 50.000 ohm ra d io volume c o n tr o l f o r r e s i s t a n c e s o f t h a t o rd e r o f m agnitude, and t h a t a one megohm c o n t r o l was s a t i s f a c t o r y f o r h ig h e r r e s i s t a n c e s . These c o n tr o l s w ere in c o rp o ra te d i n -21- th e f i n a l b r id g e c i r c u i t a s shown q u ite s c h e m a tic a lly in F ig u re I . The ground in d ic a te d was a w a te r p ip e . O p e ra tio n : In u se, th e conductance c e l l (B_J formed 1 X th e f o u r t h arm o f th e b r i d g e . A f t e r an ap p ro x im atio n of th e r e s i s t a n c e was o b ta in e d , B^, Bg, , th e o s c i l l a t o r b r id g in g t r a n s f o r m e r, and the n u l l - p o i n t tr a n s fo r m e r were s e t to approxim ate m atch es, w ith th e k n i f e of SW^ c o n n e c te d t o th e j u n c t i o n of and S g . Then was a d ju s te d f o r a minimum o f th e n u l l - p o i n t i n d i c a t o r , a s i n th e s e c t i o n d e s c r ib in g th e l a t t e r * s use (page 1 5 ). The ta p sw itc h , SW, , which allow ed c u r r e n t to flow in th e b r i d g e p ro p e r, was d e p re sse d o n ly a s needed f o r t h i s and a l l subseq uent a d j u s t ments* F ollow ing t h i s , 3W ;l was r e v e r s e d ; and th e p ro p e r p o te n tio m e te r , w hich was thrown i n t o th e grounding c i r c u i t by SWg, was a d ju s te d f o r a minimum o f p o t e n t i a l i n th e n u l l c i r c u i t . T his l a s t o p e r a tio n p la c e d th e j u n c tio n o f and Bx a t c lo s e to ground p o t e n t i a l . Then SW^ was r e v e r s e d , a new minimum o f B, o b ta in e d , and th e p ro cess d e s c rib e d box above r e p e a te d u n t i l c o n s ta n t s e t t i n g s were o b ta in e d f o r th e p o te n tio m e te r s e t t i n g and Two or t h r e e c y c le s were o r d i n a r i l y s u f f i c i e n t to a t t a i n such c o n sta n c y . With p r a c t i c e , a r e s i s t a n c e r e a d in g was o b ta in a b le i n l e s s th a n a m in u te . A ccuracy o f th e b r i d g e : The p r e c i s i o n o f th e b r id g e w ith in th e l i m i t s of 100-100,000 ohms, and 100-5000 c y c l e s , was w i t h i n a fe w -te n th s of a p e r c e n t , a s judged by measurements on v a rio u s f ix e d r e s i s t o r s . Below abo u t 100 ohms* the -22- r e p r o d u c i b i l i t y was w i t h i n a few ohms* Above 100,000 ohms o r so th e p r e c i s i o n was a l s o n o tic e a b ly p o o re r, a lth o u g h s t i l l w i t h in a few p e rc e n t even a t one megohm* Since Bx = x Bg/E1 , and was d ete rm in a b le w ith e x c e ll e n t p r e c i s i o n in d e p e n d e n tly of th e s e p a r a te a b s o lu te v a lu e s o f B-^ and Bg (Appendix 1) * th e a b s o lu te v a lu e s o f Bx depend on th o se of ^ o x * J?rom what has been d is c u s s e d , i t i s s a fe to say t h a t betw een 100 and 100,000 ohms, and betw een 100 and 5000 c y c l e s , r e s i s t a n c e s were o b ta in e d w i t h in an a c c u ra c y of t 2$. Ehe v e ry n o t i c e a b l e q u a d ra tu re o f th e 100,000 ohm u n i t s in i* makes i t n e c e s s a ry box to c o n s id e r m easurem ents above t h i s range a s u s e f u l f o r com parative p u rp o se s only* Below about 100 ohms, a c c u ra c y o f ±&fo was o b ta in a b le , w ith th e u s e f u l low er l i m i t a t about 20 ohms* - 2 3 - Z . C o n d a c tiv ity C e l l s . Two g e n e ra l k in d s of c e l l s I were used i n t h i s s t u d y . A g l a s s tu b e w ith two m e t a l l i c w ire s s e a l e d th ro u g h i t in to t h e b o re i s an example of one ty p e . Such c e l l s w ere s e a le d a f t e r t h e sam ples had been p la c e d i n them. The o th e r ty p e c o n s i s t e d of a c y li n d e r of monel m e ta l, s u i t a b l y bored and i n s u l a t e d so t h a t th e c y li n d e r i t s e l f was one e l e c t r o d e , and a clo s e - f i t t i n g p lu n g e r th e o t h e r . More d e t a i l e d d e s c r ip tio n s f o llo w . S ealed g l a s s c e l l s : The f i r s t c e l l s used in t h i s i n v e s t i g a t i o n w ere made by s e a l i n g p la tin u m w ire s a b o u t .020 in c h e s in diam eter in to s o f t - g l a s s tu b e s a b o u t 6-10 m il l im e te r s in o u ts id e d iam eter and 6 in c h e s lo n g . The w ir e s were f i r s t s e a le d in g la s s b e a d s , and th e beads th a n s e a l e d i n t o h o le s blow n i n th e s id e s of th e tu b e s , fo llo w in g te c h n iq u e s t h a t a r e d e s c r ib e d i n any s ta n d a r d r e f e r e n c e on 15 g la s s m a n ip u la tio n . Such c e l l s were used f o r m easuring the c o n d u c t i v i t i e s o f anhydrous sodium p a l m i t a t e . (C hapter I I I ) . When i n v e s t i g a t i o n of sam ples c o n ta in i n g w a te r was s t a r t e d , i t was found t h a t c e l l s o f th e ty pe d e s c rib e d blew up under the vapor p r e s s u r e s of w a te r a t the h ig h e r tem pera t u r e s encountered* A f te r c o n s id e r a b le e x p e rim e n ta tio n a s a t i s f a c t o r y d e s ig n to e lim in a te t h i s d i f f i c u l t y was d e v is e d . E i t h e r Kovar o r tu n g s te n e le c t r o d e s of about .020 in ch es in - 2 4 - diam ete r were u se d , th e fo rm er s e a le d i n C orning g la s s #7051J , and th e l a t t e r i n #7.72* Two of th e s e e le c t r o d e s were s e a le d , p a r a l l e l to one a n o th e r , i n a head o f th e p ro p e r gL ass, and th e head th e n s e a le d i n t o an open end of a tuh e o f th e same gL ass. Most c e l l s o f t h i s type were about 6" lo n g o r i g i n a l l y , and ab o u t 7 m il lim e te r s i n o u ts id e d ia m e te r, w ith w a l l s o f abo ut 0 .8 m illim e te r s in th ic k n e s s ; -when v e r y h igh v ap o r p r e s s u r e s o f w ater were e n co u n tered , tu b e s w ith t h i c k e r w a l l s were u se d . The d is t a n c e s between c e n t e r s o f th e p a r a l l e l w ire s v a rie d from about 1 /4 in c h to l / 8 in c h , and th e w ire s extend ed i n t o th e c e l l between l / 8 in ch and 3 /8 in c h . Such c e l l s a re r e f e r r e d to as " p a r a l l e l - w i r e " c e l l s . The o x id iz e d s u r f a c e s of th e Kovar w ire s in th e 16 c e l l s were c le a n e d , as recommended by the m a n u fa c tu re r, w ith n i t r i c and h y d ro c h lo ric a c i d s , fo llo w ed by r i n s i n g s w ith lim e -w a te r, and th e n s e v e r a l w ashings w ith d i s t i l l e d w a te r , a lc o h o l, and e t h e r b e f o r e u s in g th e c e l l s . I t was found p o s s i b l e t o c le a n th e tu n g s te n w ire s w ith m olten p o ta ssiu m n i t r i t e . A g r e a t d e a l of t r i a l and e r r o r e x p e r i m e n ta tio n was n e c e s s a ry to f i n d th e optimum c o n d itio n s under which t h e oxide was removed, b u t th e e le c tr o d e s them selves n o t d e s tr o y e d . A f t e r th e tre a tm e n t w ith th e m olten s a l t , th e c e l l was p re p a re d f o r use as d e s c r ib e d f o r th e "Kovar" c e l l s above. In o rd e r t h a t r e s i s t a n c e m easurements o b ta in e d in - 2 5 - d i f f e r e n t c e l l s c o a id "be compared, and to conform to s ta n d a rd p r o c e d u r e s , a l l such measurements were c o n v e rte d to s p e c i f i c r e s i s t a n c e s * This was accom plished hy f i l l i n g th e c e l l s w ith s o l u t io n s o f a c e t i c a c i d of known c o n c e n tr a t i o n s , and m easuring t h e i r a l t e r n a t i n g - c u r r e n t r e s i s t a n c e s a t 25°G. From th e known e q u iv a le n t c o n d u c t i v i t i e s o f a c e ti c 17 a c id (A ) a t v a r io u s m o l a r i t i e s (C), and th e measured r e s i s t a n c e s o f c e l l s f i l l e d w ith a c i d (B •,-,)* i t was 0 6 xx p o s s i b l e to c a l c u l a t e th e s p e c i f i c r e s i s t a n c e s o f th e a c id s fR and to d e fin e a " c e l l c o n s t a n t ” (K), f o r any c e l l , a c i c l t h u s : A = ^°0Q ■ r : 8 ., * 1000 S a c id X ° a 0 ld A x C K s " c e l l c o n s t a n t ” = Sc e n ^ a c id I t i s e v id e n t t h a t t h e s p e c i f i c r e s i s t a n c e of any su b sta n c e i n a c e l l c a n be o b ta in e d by d iv id in g th e measured r e s i s t a n c e o f t h a t s u b s ta n c e by th e "ceQLl c o n s t a n t ” (K), o f t h a t c e l l* The d e s c r i p t i o n o f each c e l l in th e d a ta of t h i s i n v e s t i g a t i o n in c lu d e s the c o n s t a n t , K, a s w e l l as a d e s c r i p t i o n of the type and th ic k n e s s of g l a s s , and a s ta te m e n t of th e e le c tr o d e m a te r ia l* The ra n g e s o f te m p e ra tu re and com po sition of soap- w a te r system s i n w hich th e s e c e l l s can be used to make r e s i s t a n c e m easurements a r e l i m i t e d by v a rio u s f a c t o r s . Among them a re ( l ) th e upper l i m i t o f r e s i s t a n c e s m easurable -26- on th e b r i d g e ( l megohm), f a r t h e r l im i te d by th e high c e l l c o n s t a n t s , and (2) the observed la c k o f e le c tr o d e c o n ta c t i n c e r t a i n r a n g e s . I t was found t h a t th e c o n d u c t i v i t i e s of th e soaps s'f-ud.ie'd d e c re a se d r a p i d l y w ith d e c re a s in g te m p e ra tu re s and w a t e r - c o n t e n t s . This o b s e r v a tio n , to g e th e r w ith th e l i m i t a t i o n s above, p re c lu d e d th e p o s s i b i l i t y of s tu d y in g soap- w a te r system s w ith p a r a l l e l - w i r e c e l l s in a t l e a s t one p r e v i o u s ly m entioned te m p e ra tu re -c o m p o s itio n re g io n o f g r e a t s i g n i f i c a n c e , namely t h a t below 100°C and below 50-60^ w a te r c o n te n t. A ttem pts to s tu d y t h i s r e g io n le d to th e develop ment o f a c e l l d e s c rib e d below. The P lu n g er C e l l : A ttem pts to measure th e conductances o f th e c o n c e n tr a te d soaps a t e i t h e r low te m p e ra tu re s (100°G o r l e s s ) o r w ith l e s s th a n a few p e r c e n t w ater, o r b o th , b ro u g h t f o r t h s e v e r a l p e rp le x in g e x p e rim e n ta l d i f f i c u l t i e s . The h a rd n ess of* such sam ples made i t d i f f i c u l t to a t t a i n e le c tr o d e c o n t a c t , and th e low e l e c t r i c a l c o n d u c t iv i t y , p a r t i c u l a r l y o f the sam ples low in w a te r c o n te n t, made i t n e c e s s a r y to d e sig n a c e l l w ith a low c e l l c o n s t a n t , nKtT , as d e fin e d i n th e p re v io u s s e c t i o n . F u rth e rm o re , th e p r o b a b i l i t y o f l o s i n g some o f th e w a te r c o n te n t d u rin g h e a tin g of th e samples meant t h a t an open c e l l was u n d e s i r a b l e . I t was d ecid ed to a tte m p t to o b ta in e l e c t r i c a l c o n t a c t , o r a t l e a s t some r e p r o d u c ib le m easurem ents"of r e s i s t a n c e , by a p p ly in g c o n t r o l l a b l e p r e s s u r e betw een the - 2 7 - e le c tro d e s * The c e l l f i n a l l y developed i n an a tte m p t to a cc o m p lish t h i s and t o f i l l th e o th e r needs s t a t e d i n th e p a ra g ra p h above i s drawn to f a l l - s c a l e i n P ig u re IV, which i s l a r g e l y s e l f - e x p l a n a t o r y . P r e s s u r e was a p p li e d a s needed by p l a c in g th e c e l l betw een th e p l a t e s of a C arver P r e s s w h ich was c a p a b le of p ro d u c in g p r e s s u r e s as h igh as 2Q,000 pounds p er sq u a re in c h . The n eoprene g a s k e ts i n the c e l l were of a type used in h y d r a u lic m achinery. The l i t t l e screw a t the top of th e low er e le c t r o d e had l e f t - h a n d e d th re a d s and was s l o t t e d . I t co u ld t h e r e f o r e be removed i n o rd e r t h a t the b otto m e le c t r o d e c o u ld i n t u r n be p u l l e d up by means o f a p r o p e r ly - th r e a d e d rod w ith a h a n d le . The sam ples u sed were g e n e r a l l y under 3 m il l im e te r s i n t h i c k n e s s , and th e soap powders from w h ic h th e y were formed w ere p lac ed i n t h e c e l l a f t e r th e s u r f a c e s to be touched by them had been th o r o u g h ly c le a n e d and r in s e d w ith a lc o h o l and e t h e r , and th e c e l l th e n d r ie d i n an ov en a t 105°C. The c e l l was d esig ned to make i t p o s s ib le to c a l c u l a t e c e l l c o n s ta n ts from i t s geom etry and th e t h i c k n e s s e s o f th e sa m p les, and th u s to c o n v e rt measured r e s i s t ances t o s p e c i f i c r e s i s t a n c e s . However, s in c e th e data o b ta in e d were used o n ly t o p l o t t e m p e r a t u r e - r e s is t a n c e c u rv e s , as d e sc rib e d i n Chapter IV, i t was n o t n e c e s s a r y to c o n v e rt measured r e s i s t a n c e s to s p e c i f i c r e s i s t a n c e s d uring th e c o u rse o f th e i n v e s t i g a t i o n w i t h th e p lu n g er c e l l . Jir\ less NJeopr&nc ft o b be \ rr> p r i g r\* C ambnc irxeiv ikt *'rn© m e. 4ev^ -29^ 3, Ovens and t h e r m o s t a t t i n g Arrangements th e low h e a t - c a p a c i t y of t h e s e a le d g la s s c e l l s - made i t p o s s ib le to v a r y th e te m p e ra tu re s of sam ples in them by h e a t in g or c o o lin g them i n an a i r oven. On th e o t h e r hand, t h e v e r y la r g e hestt ^ c a p a c ity of th e p lu n g e r - ty pe c e l l made i t im p e ra tiv e t o h e a t or c o o l i t w i t h a l i q u i d , th e d e t a i l s f o r v a ry in g the te m p e ra tu re s o f th e s e two^ types of c e l l s fa llo w : th e Oven f o r th e S e a le d G lass C e l l s : t h i s oven had double w a l ls o f s h e e t m e ta l, and was i n s u l a t e d w ith s e v e r a l l a y e r s of a s b e s to s paper around the o u t s i d e , a s b e s to s f i b e r betw een t h e w a l l s , and a l a y e r o f a s b e s to s paper around th e in n e r w a l l . About 35 ohms o f nichrome w ir e , wound around the in n e r l a y e r o f a s b e s to s p a p e r, se rv e d as t h e h e a t i n g e le m e n t, th e oven r e s t e d on b r i c k s on t h e l a b o r a t o r y t a b l e , two g la s s windows, f r o n t and ba ck , each abou t 3 in ch es by 4 in c h e s , were p ro v id e d f o r v i s u a l o b se rv etio n * t h e oven, was a b o u t 12 in ch e s h ig h by 9 in ch es s q u a r e , and was f i t t e d w ith a w e l l - i n s u l a t e d rem ovable t o p . C i r c u l a t i o n of a i r was m a in ta in e d by an e l e c t r i c a l l y - d r i v e n s t i r r e r . t h e v o lta g e a c ro s s t h e r e s i s t a n c e w ir e , and th u s th e r a t e o f h e a t i n p u t , was c o n t r o l l e d by a V a ria c t r a n s fo rm e r. th e te m p e ra tu re c o n t r o l p o s s ib l e by t h i s a r r a n g e ment was s u f f i c i e n t to o b t a i n th e data d e s i r e d , as d e s c r ib e d i n succeed ing c h a p te r s . - 3 0 - I t was n e c e s s a ry to r u l e o u t th e p o s s i b i l i t y t h a t tem p era tu re g r a d ie n ts m ight e x is t i n th e oven. This was done by i n s e r t i n g the b u lb s o f s e v e r a l c a l i b r a t e d therm om eters i n t o d i f f e r e n t p a r t s o f th e volume o f th e oven. Both v e r t i c a l l y and h o r iz o n ta lly * and a t d i s t a n c e s much c l o s e r to th e w a l ls th a n any sam ples w ere s u b s e q u e n tly p la c e d , ho g rad i e n t s o f more t h a n a degree or two were found to e x i s t a t any te m p e ra tu re in th e range £0° - 300°C. T h e rm o s ta ttin g A rrangem ents f o r th e P lu n g e r C e l l : In u se , t h e p lu n g er c e l l was p lac ed i n a s t a i n l e s s - s t e e l c y l i n d r i c a l c a n , open a t th e top* and about 10 in c h e s h ig h and 6 in c h e s i n d ia m e te r. S e v e ra l l a y e r s o f a s b e s to s paper were wound around th e can f o r i n s u l a t i o n . The c e l l in the can was th e n p la c e d i n th e C arver P re ss and c e n t e r e d . C onnections w ere made to t h e b rid g e b y a t t a c h i n g c l i p s t o th e can and t o th e p lu n g e r. The can was d r i l l e d and f i t t e d w ith t h r e e c i r c u l a r lip p e d openings each abo u t 5/8 in ch es i n d ia m e te r. One was v e ry c lo s e t o th e b ottom , th e second j u s t, below th e h e ig h t t o which th e ja c k e t o f t h e can re a c h e d , and th e t h i r d o f the r i g h t h e ig h t to a llo w a c a l i b r a t e d therm om eter . f i t t e d ‘ W ith a neoprene s to p p e r t o 'b e i n s e r t e d through'Jfche can and vV. • • in to the c e l l a f t e r th e l a t t e r two had been a l i g n e d . The thermos t a t t i n g l i q u i d , b u t y l p h t h a l n t e ; , was chosen f o r i t s low v i s c o s i t y , high b b i l i n g p o i n t , and low t o x i c i t y . I t was f o r c e d by a sm a ll c e n t r i f u g a l pump in to th e a n n u la r space betw een th e can and th e c e l l . The l i q u i d e n te r e d t h i s space through th e bottom h o l e , and - 3 1 - l e f t fry g r a v i t y through, a 1 /2 in c h -d ia m e te r tufre le a d in g to th e r e s e r v o i r , which was a p y rex j a r h o ld in g abo u t 2 g a llo n s o f th e l i q u i d . The tem p era tu re o f th e h a th was 18 c o n t r o l l e d fry a method d e s c r ib e d e ls e w h e re . I l l c o n n e c tio n s were of g l a s s tu b in g , or neoprene tu b in g and sto p p e rs where n e c e s s a r y . The l a t t e r sw e lle d i n use, e s p e c i a l l y over long p e rio d s o f tim e o r a t te m p e ra tu re s above 80°C, b u t were re a so n a b ly s a t i s f a c t o r y o th e rw is e i f re p la c e d every few weeks of d a il y u se . The maximum te m p e ra tu re a t w hich t h e arrangem ent d e s c r ib e d was used was 100°C. C o n tro l o f th e tem p era tu re o f t h e c e l l was p o s s i b l e to -0.5°C* a lth o u g h to m a in ta in te m p e ra tu re s of l e s s th a n 35°C, i t was n e c e s s a r y to p ro v id e sup plem entary c o o lin g o f the b a t h . T his was accom plished by th e use o f a c o o lin g c o i l i n t h e b a t h th ro u g h w hich t a p w a te r co u ld be c o n s t a n t l y p a s s e d . T heptem perature of th e c e l l co u ld b e r a i s e d a s r a p i d l y as a degree every few m inutes., A lthough i t was n o t p o s s i b l e to measure the te m p e ra tu re s of th e sam ples d i r e c t l y , th e p r o x im ity o f the therm om eter b u lb to t h e sam ples and th e h ig h h e a t c o n d u c tiv i t y of the m etal make i t sa fe to sa y t h a t no a p p re c ia b le e r r o r was made i n ta k in g t h i s te m p e ra tu re as t h a t o f the so a p s. B . M a t e r ia ls - 3 5 - I t i s r e l a t i v e l y d i f f i c u l t to p rep a re pure s i n g l e f a t t y a c id s and t h e i r s a l t s . Because of t h i s and the p o s s ib le dependence of th e conductance of such s a l t s on sm a ll amounts of im p u r itie s * th e s o u rc e s and methods of p r e p a r a t i o n o f the sodium p a lm i ta te and sodium s t e a r a t e used i n t h i s i n v e s t i g a t i o n a r e d e s c r ib e d below . 1 . Sodium P a lm ita te The sodium p a lm ita te used was o f th e same s to c k 1 9 whose p r e p a r a t i o n has been p r e v io u s ly d e s c r ib e d . E. Sodium S t e a r a t e The m ajor e f f o r t s and f i n d i n g s o f t h i s i n v e s t i g a t i o n were on th e c o n d u e tim e trie b e h a v io r of sodium s t e a r a t e w a ter sy stem s. For t h i s re a so n th e s t e a r i c a c id used was p re p a re d w ith g r e a t c a r e . The p ro c e d u re d ev ised i s now SO ' d e s c rib e d in th e l i t e r a t u r e , and the f i n a l p r e p a r a t i o n El and d ry in g o f th e sodium s t e a r a t e i s d e sc rib e d e ls e w h e re . W ith the e x c e p tio n o f about two grams of .s te a ric a c id o b ta in e d by I1. F ra n c is and S. H. P i p e r , th e a c id o b ta in e d in th e p r e s e n t stu d y i s p ro b a b ly p u r e r th an any o th e r s t e a r i c a c i d ev er r e p o r te d . The subsequent, p r e c a u tio n s ' Zt tak e n in th e n e u t r a l i z a t i o n o f th e a c id , p a r t i c u l a r l y to avo id an e x c e ss o f b a se and th u s in tr o d u c e an e l e c t r o l y t i c Z t i m p u r ity ,' t o g e t h e r w i t h t h e degree o f p u r i t y of the a c id , make i t s a f e to say t h a t th e sodi urn, s t e a r a t e used i n t h i s - 3 4 - i n v e s t i g a t i o n is p ro b a b ly th e p u r e s t e v er prepared.. The s ta te m e n ts above a r e p re s e n te d "because th e y may be o f some im portance w ith r e f e r e n c e to th e v a l i d i t y o f th e i n t e r p r e t a t i o n s o f th e a b s o lu te v a lu e s of th e conductances o b ta in e d fo r sodium s t e a r a t e system s (C hapter IV ). -35 CHAPTER I I I CONDUCTIYITIES OF ANHYDROUS SODIUM PALMITATE The f i r s t c o n d u c t iv i t y measurements made i n th e p r e s e n t i n v e s t i g a t i o n were on anhydrous sodium p a l m i t a t e . S e v e ra l im p o rta n t f a c t s were e s t a b l i s h e d : (1) As th e tem p era tu re was r a i s e d , conductance was f i r s t m easurable w ith th e equipment used* a t 239°C; (2) nb r e a k s !f, i n th e lo g a r ith m of r e s i s t a n c e v s. te m p e ra tu re ( ?,LRTU) c u rv e s, as d e s c r ib e d i n C h apter IY, o c c u rre d s u b s e q u e n tly a t 255° and 295°; (3) a d d itio n s of l e s s th a n 1% w a te r to th e soap low ered q u i t e m arkedly th e te m p e ra tu re a t which conductance was f i r s t m easu rab le; and (4) w ith in re a s o n a b le l i m i t s , th e same r e s is t a n c e ^ te m p e r a tu r e v a lu e s.w e re o b ta in e d upon h e a tin g and c o o lin g . Item s ( l) and (3) showed t h a t th e c e l ls , and e q u ip ment used w ere s u i t a b l e f o r stu d y in g c o n c e n tr a te d system s o f soap in w a te r, p a r t i c u l a r l y a t h ig h e r t e m p e r a tu r e s , b u t a ls o a t low er te m p e ra tu re s a f t e r a d d it i o n s of sm a ll p e rc e n ta g e s o f w a te r . Item s (2) and (4) f u r t h e r showed t h a t d a ta o b ta in e d i n such s t u d i e s c o u ld be used f o r phase-change i n t e r p r e t a t i o n s , s in c e 256°, and 295° ag re e *In th e p r e lim in a r y s e t o f experim ents th e so u rce o f v o lta g e f o r t h e b r id g e was an 1000 cy cle microphone hummer (G eneral Kadio Type 21 3 ), th e n u l l - p o i n t i n d i c a t o r a p a i r o f e a rp h o n e s, and Bp and B£ a s l i d e - w i r e o f a s t u d e n t- t y p e p o te n tio m e te r (Leeds & N o rth ru p #7651). - 3 6 - w e ll w ith p r e v i o u s ly e s t a b l i s h e d phase t r a n s i t i o n s a t n I 0 253u and 296 . D e t a i l s of the e x p e rim e n ta l work f o 11 ow. Sodium p a l m i t a t e powder, p r e v i o u s ly d r i e d to 18 c o n s ta n t w e ig h t, and k e p t i n a c lo s e d w eighing b o t t l e i n a d e s i c c a t o r f i l l e d with anhydrous c a lc iu m c h l o r i d e , was used t o f i l l a lfw i r e ,f conductance c e l l w ith p latin u m e l e c t r o d e s , as d e s c r ib e d in C hapter I I , to a h e ig h t of a b o u t t h r e e inches* The to p was th en s e a le d o f f w ith care, t o a v o id s c o r c h in g . S e a lin g to o k p la c e w ith in not more th a n one m inute a f t e r th e a d d i t i o n o f the soap powder, which had been kept c o rk e d in t h e c e l l . The c e l l was th e n h e ated to about 300°0, a t which te m p e ra tu re 18 th e soap i s i n th e form o f a l i q u i d , and th e n allow ed to co ol i n the oven to room t e n p e r a t u r e . The e le c t r o d e s were b ro u g h t o u t thro ugh th e to p of th e oven, conn ected to th e b r i d g e , and r e s i s t a n c e m easurements made a s the te m p e ra tu re was v a r i e d . T em peratures w ere m easured w ith a c a l i b r a t e d therm om eter, and t h e r e s i s t a n c e s o b ta in e d c o n v e rte d to s p e c i f i c r e s i s t a n c e s fro m -th e c e l l c o n s t a n t , "K" (C h ap ter I I ) , o f 4 .3 3 . C e ll r e s i s t a n c e s were o b ta in e d a f t e r th e oven had been b ro u g h t to a te m p e ra tu re a t which a measurement was to be made, and the oven was th e n kept a t t h a t te m p e ra tu re u n t i l a re a so n a b ly c o n s ta n t v alu e f o r th e r e s i s t a n c e was o b ta in e d . A few m inutes was s u f f i c i e n t time to a t t a i n - 3 7 - such c o n sta n c y a t a l l te m p e ra tu re s u sed . The d a ta , w ith the t e m p e r a t u r e - r e s i s t a n c e m easurem ents l i s t e d ch ron o l o g i c a l l y , a re summarized in Table I I , and p l o t t e d on th e custom ary "LET" a x es (C hapter lY) i n F ig u re Y. B e s is ta n c e measurements were made th ro u g h s e v e r a l c y c le s of h e a tin g and c o o lin g . The d egree o f r e p r o d u c i b i l i t y o f th e d a ta upon h e a tin g and c o o lin g makes i t sa fe to say t h a t i f any g ra d u a l th e rm a l d eco m position or o x id a tio n by adsorbed a i r o c c u rre d , th e e f f e c t was to o sm all to be o f consequence i n th e p r e s e n t i n v e s t i g a t i o n * Such r e p r o d u c i b i l i t y a ls o su g g e sts th e e x is te n c e o f a d eq u a te c o n ta c t of th e soap w ith th e e l e c t r o d e s . T his q u e s tio n i s c o n sid e re d a t g r e a t e r le n g th in C hapter IY. ‘ The o t h e r c o n c lu sio n s ite m iz ed a t th e b e g in n in g o f t h i s c h a p te r a r e e v id e n t from t h e d a t a , e x cep t f o r item ( 3 ). That c o n c lu s io n was e s t a b l i s h e d by opening th e c e l l , adding l e s s th an ifo w a te r to the anhydrous sam ple, r e s e a l i n g th e c e l l , hom ogenizing t h e c o n te n ts as d e s c r ib e d i n C h a p te r IY, and th e n m easuring th e co n ductances of th e sample a s a f u n c t i o n of th e te m p e ra tu re . Since th e d a ta o b ta in e d f o r the anhydrous sodium p a lm i ta te sample a re so s i m i l a r q u a l i t a t i v e l y to th o se o b ta in e d fo r sodium s t e a r a t e , th e i n t e r p r e t a t i o n s of th e c o n d u e tim e tric b e h a v io r of t h e two a r e d e fe rre d i n t h i s r e p o r t u n t i l C hapter IY, where th e d a ta f o r sodium s t e a r a t e are p r e s e n te d . - 3 8 TABLE I I SPECIFIC RESISTANCES OF SODIUM PALMITATE 0*0# Water - About 1000 Cycles Measurements Obtained Measurements obtained On Heating On Cooling T°C mm v ' R-ohms T6C R-ohn 239 150M 308 350 240 90M 295 370 242 62M 291 420 243 32. 3M 288 460 245.5 18. O M 256 740 253 2550 256 760 274 855 * 256 810 281 785 253 2150 286 760 248- 9200 291 690 245 32.0M 297 645 244 50.6M 304 350 3L0 320 317 360 315 300 289 420 i • • • • • 249 e • • e 7850 255 1150 261 1010 267 880 288 690 293 690 295 340 297 340 , * 310 440 MO6 5* 10' F « 2* io5 *IO 5-ici4 jC °<2M04 j -j < -21 *|Q4 * a : S'lfO3- o 0 o □ Q d G 0 G S p e c i f it. R e i i s 4 J « c e s o f f\I 0 . 0 °7o H ^ O A to * 4 iO O O Cydi O M * o » u ^ e , n * i i 4 4 o t 4 * n a c ( J u j kv. e k . t < ) 4 e J □ M e« ? 5 o r £ 4 j o £ > i * ( , u->K«n t o o I t J, I T e uipeKdtwrtti of p^Cviow ily repor-4vJ p 4^ <*:*«. 4 ir d) r v s l 4. l o r v s . ( O 2*10* o 0 1*10' 5*10* 2-10* *10* o 0 Q G □ 24-0 G Q O O Q o %n G § 0 0 % ° 0 260 280 Te-m p * T « J toire ® C . iOO 3-L O - 4 0 - CHAPTER IY CONDUCTIVITIES OF SODIUM STEARATE-WATER SYSTEMS OF DOW WATER CONTENT A* l £ S ealed C e lls 1» P r e p a r a t io n of Samples E le v en sam ples o f sodium s t e a r a t e w ith w a te r c o n te n ts ra n g in g from 0 .0 to 1 2 *Sf0 were p r e p a r e d . A t y p i c a l p ro c e d u re fo llo w s: A " p a r a l l e l - w i r e " c e l l , f i t t e d w ith a c o rk , was weighed and a s m a ll amount of w a te r added w ith a c a p i l l a r y p i p e t to th e "bottom of the c e l l , which was th e n rew eighed. Sodium s t e a r a t e powder, p r e v io u s ly d r i e d to c o n sta n t w e i g h t ,1® was th e n added, and th e c e l l a g ain rew eig h ed .* The s iz e o f th e sample was g e n e r a l l y under 0 .5 gram. S e a lin g o f the c e l l was accom plished w i t h a h ot flam e and a t l e a s t 4 c e n tim e te r s away from th e top o f th e sample to guard a g a i n s t b u r n in g . Hom ogenization to o k p lao e by h e a t in g to t h e v i c i n i t y o f 300°C i n th e oven d e s c rib e d i n *Sodium s t e a r a t e powder i s q u ite h y g ro sc o p ic . For t h i s re a s o n , i t was added a s r a p i d l y as p o s s ib le (th ro u g h a p a p e r f u n n e l ) , and th e c o rk r e - i n s e r t e d . A fte r th e soap powder had b e e n poured in to th e f u n n e l, a p ro c e ss w hich took n o t over a few se co n d s, th e sample b o t t l e was c l o s e d . Then th e soap was fo rc e d th ro u g h th e fu n n el by sh a k in g and by t h e use of a w i r e . The time of c o n ta c t of any soa$ sample w ith th e a i r o u ts id e of th e conductance c e l l was c e r t a i n l y not over two m in u te s, and p ro b a b ly l e s s th a n one minute f o r most of th e sa m p les. As many a s s i x samples were removed from t h e sample b o t t l e w ith o u t r e - d r y i n g th e powder i n i t . - 4 1 - O hapter I I , and th en i n v e r t i n g the, tube 15-20 tim es by means of a rod w hich was clamped to t h e tube and was r o t a t a b l e from the o u ts id e o f th e oven* A fte r c o o lin g , th e c e l l was broken a t th e top* and a g la s s rod o f the l a r g e s t p o s s ib l e d ia m e te r and le n g th in se rte d ,, a f t e r which t h e c e l l was re se a le d * The l a s t s te p was n e c e s s a ry to in su re t h a t no s i z e a b le f r a c t i o n of the w a te r p re s e n t i n th e system would be i n t h e vapor phase , th u s changing th e com position of th e condensed system . C a lc u la tio n s ta k in g in to account th e v a p o r p r e s s u r e o f w ater a t th e h i g h e s t te m p e ra tu re en coun tered (300°C), t o g e t h e r w ith the assum ptions of th e i d e a l gas law and h a o u l t fs law ,* showed t h a t th e e s tim a te d a i r space re m a in in g would c o n ta in only a n e g l i g i b l e f r a c t i o n of t h e w ater c o n te n t of any c e l l . Such a c a l c u l a t i o n is shown i n Appendix 2. The c o n te n ts of the c e l l were th e n a g a in homogenized, and allow ed to cool i n th e c lo s e d oven to about 50° - 60°C b e fo re b e in g removed. The r a t e o f c o o lin g was such t h a t i n a t y p i c a l e x p e rim e n t, a te m p e r a tu re of 200°C was a t t a i n e d in abou t 20 m in utes, 150°C i n ab ou t 55 m in u te s, and 10Q°C i n about 60 m inutes* The cover of the oven was th e n p a r t i a l l y removed, th e oven allo w ed to cool to about 50° - 60° i n 15 minutes,, an d th e c e l l removed. *These a ssu m p tio n s, w hich a r e c e r t a i n l y f a r from c o r r e c t , a r e j u s t i f i a b l e in th e absence o f data re g a r d in g vapor p r e s s u r e s of such s y s te m s , s in c e the c o r r e c t i o n s o b ta in e d a r e s m a ll. - 4 2 - 2. Conductance Measurements S e v e ra l c e l l s were clamped v e r t i c a l l y in th e oven, and w ir e d so t h a t t h e r e was one common e le c tr o d e f o r th e group and an a d d i t i o n a l le a d f o r each c e l l . The le a d s were b ro u g h t out th ro u g h g la s s tu b e s which i n t u r n were le d th ro u g h th e to p of th e oven, and th e n to a te r m in a l s t r i p . Che p ro p e r c h o ic e o f te r m in a ls a llo w e d any c e l l i n th e oven to become f o r th e b rid g e* The c o n te n ts of th e c e l l s t o g e t h e r w ith a d e s c r i p t i o n of the e l e c t r o d e s , th e c e l l c o n s t a n t s , and th e s i z e s o f th e tu b e s , a re shown i n Table I I I . R e s is ta n c e measurements w ere made a t a s e r i e s o f te m p e ra tu re s f o r each c e l l ; f o r co m parative p u rp o se s, a l l m easurements were c o n v e rte d to s p e c i f i c r e s i s t a n c e s . Tem peratures w ere m easured w ith c a l i b r a t e d therm om eters, p la c e d a s c lo s e to th e c e l l s as p o s s ib le * S p e c if i c r e s i s t a n c e s o b ta in e d a t v a rio u s te m p e r a tu re s , t o g e th e r w ith th e f r e q u e n c ie s a t w hich th e y were o b ta in e d , and th e r a t e s of h e a t in g or c o o lin g , a re shown f o r each sample i n T ables IV to X I I I , and graphed i n F ig u re s VI to XV. U n le ss o th e rw ise s t a t e d , runs were made a s th e tem p era t u r e was in c r e a s e d . The v e ry la r g e r a t i o betw een th e h i g h e s t and lo w est r e s i s t a n c e s f o r most sam ples, more th a n 4 10 i n many c a s e s , n e c e s s i t a t e s th e use o f s e m i-lo g a rith m ic graphs i f th e d a ta f o r one sample a re to be shown on one p l o t of re a so n a b le s i z e . The d a ta w ere a ls o p l o t t e d on -H 3 - TABLE HI IDEJTIFICATIONOF SAMPLES OF SODIUM STEARATE WITH LOW WATER CONTENT Sample No* * % Water Cell Constant Electrodes and Glass A 0*0 1.84 Kovar in 705AJ . B 0*5 1*06 Kovar in 705AJ C 1.0 0.718 Tungsten i in 772 D 2*0 1.00 Kovar in 705AJ E 2.4 \l.48 Tungsten^ln 772 F 2.5 1.14 Kovar in 705AJ H 3*3 1.32 Tungsten in 772 I 4.4 1.48 Tungsten in 772 J 6.5 1.4S Tungsten in 772 K 12.8 1.84 Tungsten in 772 All cells were 7 mm. O* D. and about 0.8 mm. wall thickness, with the exception of cell A. The latter was about 12 ran. 0. P. and about 1*5 mm* wall thickness* *AU samples were made using that fraction of the sodium stearate made from stearic acid characterized as batch "B1 1 in J* Philipson*s report^ on the preparation of stearic acid* TA B L E IV SPECIFIC RESISTANCES OF SODIUM STEARATE A 0.0$ Water - 960 Cycles First Run , Heated rapidly from room temperature' to 2L0°. Thereafter heated about 1° per 3-4 minutes* T°C R-ohms 252 8500 254*5 1250 257*5 850 260 800 264 74P 268 690 271 670 275 640 279 470 281 470 285.5 450 289.5 450 Bubbles visible until 279°. Second Run Kept at 160° overnight* Thereafter heated about 1° per 3-4 minutes* T°C r Rrohms 253 2470 256 625 260 550 263 520 266*5 485 269*5 455 273*5 450 276 420 279.5 380 283 370 287.5 350 290 350 293 335 Best run of the three from the standpoint of lack of bubbles* (Continued on Next Page) T A B L E IV (Continued) SPECIFIC RESISTANCES OF SODIUM STEARATE A 0.0% Water - 960 Cycles Third Run Kept at 240° overnigh^* Thereafter heated about 1 per 3-4 minutes# T°C , R-ohms T°C R-ohms 244 600k 266 520 245 36QM 267 555 246 240M 268 550 247 160M 269 535 248 126k 270 535 249 77M 271 610 250 28*0M 272 485 251 13.7M 273 535 252 6300 274 530 253 3150 275 550 254 1300 276 550 255 800 277 520 256 640 278 430 257 630 279 420 258 620 280 450 259 620 2a 450 260 590 282 450 261 610 283 450 262 600 284 450 263 590 285 450 264 560 286 360 265 525 287 345 288 400 -<*s- T A B L E V SPECIFIC RESISTANCES O F SO D IU M STEA R A TE B First. Run Heated to 285°, then cooled about 1° per 3-4 minutes* T°C R-ohms 284 330 277 330 273 335 269 380 265*5 380 264 380 260*5 370 257 380 253*5 400 250 425 246 580 241*5 1650 237 3400 234 6200 230 18.5M 226*5 39.5M 222 120 M 219 230 M 0*5$ Water - 420 Cycles Second Run Kept at 140° overnight* Very erratic heating because of power line failure* T°C ff-ohma 245 1700 250 1150 255 1070 263 1000 268 930 271 930 276 400 280 330 BUbble observed around electrode up to about 270° Thir d Run Heated to 300° f then cooled about 1 per 3-4 minutes. T°C R-ohms 300 295 296 305 292 305 289 300 283.5 330 281 345 277 345 272 345 • 270 345 267 350 264.5 345 262 345 261 , 345 257.5 365 253*5 385 250 415 247 435 243 1300 240 2700 table; yi SPECIFIC RESISTANCES OF SODIUM STEARATE C 1*0 Water - 960 Cycles First Run Heated rapidly from " room temperature to 210°. Thereafter Heated about 1 per 3*4 minutes# T°C R-ohms T°C 309 2620 162 2L4 1540 165.5 216 1370 168 221 1060 171.5 224.5 1010 174 228.5 960 177 231.5 943 180 235.5 920 183 238.5 910 186.5 242 910 190.5 245.5 900 193 2 48 890 198 251 875 201 254.5 860 204 257.5 865 206.5 260 875 210 264 860 214 268 850 218 271 490 221.5 275 470 279 475 281 480 285 490 289.5 540 Seoond Run Kept at'160 overnight; Thereafter heatedabout 1° per 3*4 minutes* R-ohms T°C R-ohms 72.0M 225.5 650 65.3M 228.5 615 58.4U 233.5 585 53.8M 236.5 570 50.0M 240 560 44.5M 243 555 39.2M 246 600 33.8M 252.5 585 27.6M 256 605 22.0M 260 615 18.OM 263 615 11. AM 266;5 615 8300 269.5 505 5850 273.5 500 4450 276.5 485 2550 279.5 485 1370 283 490 1010 287.5 500 785 290 515 293 515 (Continued on Next Page) T A B L E VI (C ontinued) SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E C 1*0$ Water - 960 Cycles Third Run Kept at 130° overnight; Thereafter heated about 1° per 3-4<minutes» Fourth Run Was at room temperature for a few days * Heated to 100° in 1 hour, then about "1° per 3-4 minutes* Fifth Run Kept at l00° overnight* Heated to 140° in 4 hours* Then heated at an erratic rate of from about 1? per 2-10 minutes, ' except as noted* T°C R-ohms T°C i 1 R-ohms T°C R-ohms 136 223k 140 230U 142 223M 133 690M 145*5 20711 134 610M • • . . . # 148.5 245M 135 550M 143 540M 152 161M 136 530M 148 290M)* 157*5 13UI 137 490M 148.5 260M)* 160*5 123k 138 415M 158 13dl 164 108M 140 370M Then left for 167 98.0k 142 343M 20 hours at 170°, 170 87.5M 144 30 5M and heated as before* 173 76.5M 146 275M 183 4OiOM 176 67.5M 148*5 220M 192 23.0M 179 61.5U 151 185M 19515 18.7M 182 53.0M 153 170M 204*5 8300)** 185*5 44.5k 155 147M 204 8600)** 188*5 38.5k 157 133M 217 1570 191.5 31.0k 159 123M 226 870 195*5 23.0M 161 117M 236 890)* 199 16.9k 163 110k 236 850)* 202.5 ruac 165 104k 205 8600 167 100M * Readings 30 minutes 209 5050 169 92.OM apart 212 2000 171 86.0k 2L5 1640 173 81.0M ** Readings 15 minutes 218 1380 175 75.0M apart 221 1120 178 66.0k 224.5 900 227*5 845 230 815 233 785 -MU T A B L E V II SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E D 2*0% Water - 420 C ycles First Run Heated to 285°* then cooled about 1° per 3-4 minutes* Second Run Kept at 140° overnight* Very erratic heating because of power line failure* Third Run Heated to 300°, then cooled about 1° per 3-4 minutes* T°C R-ohras T°C R-ohms T°C R-ohms 282 295 146 35.0M 300 290 277 300 151*5 28.0M 296 265 273*5 305 155 25.OM 293 255 269 295 158.5 22.2M 288*5 255 266 285 162 20*011 284.5 265 264 270 165*5 17*611 281 260 261 250 170 14*811 277*5 265 257 255 . 174 12.1M 272.5 265 254 255 - 229 330 269.5 275 250 265 233 330 . 264*5 275 246 265 236*5 320 261 265 2U. 5 270 241.5 310 258 265 237 280 245 310 253 270 234 300 250 310 250 275 230 310, 254 300 247 285 226.5 350 263 275 244 285 222 360 267 275 240 295 219 360 271 265 236*5 305 213 360 275*5 265 233 330 207 1060 280 260 228*5 350 203 1700 224*5 350 199 3150 219 370 195 5050 213 450 192*5 7800 209 660 189 12.0U 206 1030 182 25*011 203 1700 177*5 27* 5R 199 2750 174 31.0M 196 4750 170 35*011 192 810Q 167 37.QM - if 7(a)- TABLE VII (Continued) t SPECIFIC RESISTANCES O F SO D IU M S T E A R A T E D 2.0% Water - 420 C ycles Fourth Run o Kept at 170’ overnight * Thereafter heated"about 1° per 3-4 minutes* T?C 181 186 189*5 196.5 200 203 206 209 213 216.5 220 223 228 232 235*5 239 242 245 249 251.5 255 258 R-ohms 12.3m 11.3M 5500 38$0 2900 2050 990 670 385 360 340 320 315 300 300 290 285 280 275 275 ' ■ Fifth Run Kept at 230° overnights Thereafter heated about 1° per 3^4 minutes. T°C 280*5 284 288.5 291 294 297 R-ohms 260 26$ 260 260 28$ 290 T A B L E V III SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E E 2 .4 # Water - 960 C ycles First Run Heated rapidly from room temperature to 210°. Thereafter heated about 1° per 3-4 minutes# T°C . R-ohms T°C 210 375 162 213.5 380 165*5 216 380 168 220.5 380 171.5 225 375 174 228 375 177 232 375 180 235 375 183 239 375 187 242 375 190 246 375 193 248 375 197.5 251 375 201 255 375 204 257 375 206.5 260 375 210 264 375 214 268 260 218 271 255 221.5 275 255 225.5 279 255 281 255 285 255 Second Run Kept at 160° overnight. Thereafter heated about 1° per 3-4 minutes. R-ohms T°C R-ohms 3550 228.5 270 3150 233 255 2900 237 255 2600 240 255 2350 243 255 2000 246 275 1750 252 270 1550 256 280 1220 260 290 990 263 305 800 266 250 580 269 240 410 273 240 350 276.5 230 330 279.5 230 315 283 230 300 287 230 290 290 225 285 293 225 (con tin u ed on n ext page) T A B L E V III (Continued) SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E E Z * k % Water - 960 Cycles Third Run Kept at 130 over- Thereafter heated about 1 per Fourth Run Kept at 100° overnight. . Then heated about 1° per 304 minutes, except toward the end of ,the run. as noted. Fifth Run Was at room temperature for a few days* Heated to 100° in 1 hour, then about 1° per 3*4 minutes. T°C R-ohms T°C R-ohras T°C ~i*ohms 136 7400 121*5 15611 120.5 375M 139.5 6950 123 127M 122 330M 142 6550 125 90M 123 300H 145 5950 127 63. 5M 124 260M 146.5 5400 129 47M 126 195M 152 4650 131 28.5M 127 164M 157.5 4000 132 24.5M)Readings 128 149M 160*5 3650 132.5 23.5M)15 minutes apart 130 104M 164 3300 132.5 22.5M_One hour 131 85.5M 167 2950 after 132 132 74.5M 170 2600 reading 133 89.5M 173.5 2300 136 14.2M 20 hours 134 82.0M 176 2050 later 135 73.0M 179 1600 136 71.QM 1S2 1540 137 67.GM 165.5 1280 136 61.5M 188*5 1070 140 56.OM 192 860 142 45.5M 195.5 6?0 1 144 34.5M 199 202 510 146 26 .OH 390 148.5 18.7M 205 350 151 14.9M 309 300 153 12.0M 2L2 310 155 9700 215 315 157 8200 ' 159 161 163 165 167 169 171 173 175 178 6650 5600 5100 4400 3750 3300 2800 2300 1950 1650 tabLe IX SPECIFIC RESISTANCES OF SODIUM STEARATE F 2.5% Water - 420 cycles First Run Second Run ‘ - ’ ' X . ■ * V « f t o' Heated to 285 • then Kept at 14© overnight* cooled about .1 per , Vexy erratic heating be- 3-4 minutes* cause of power line failure* T°C R-ohms T°C R-ohms 262 250 - 146 4000 277 250 152 3300 273.5 230 155 3200 269 210 159 2800 266 200 162 2600 264 177 166 2300 261 177 170 2050 257 173 175 1630 254 173 179 1300 249.5 173 184 940 246 173 229.5 200 24L 173 233 200 237 182 237 200 233.5 192 24L 195 230 192 245.5 190 226 202 251 190 222 205 254 190 219 210 264 190 213 210 267 200 206 230 272 240 203 250 198 280 * 195 400 192.5 550 181 135PO 177.5 1580 173.5 1850 170 2150 166 2450 . (Continued on Next Page) - 4%*)- T A B L E IX (Continued) SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E F 2 * 5 % water - 420 Cycles Third Run Heated to 300°G, then codLed about 1° per 3- 4 minutes.______ Fourth Run Kept at 170° overnight* Thereafter heated about 1° per 3-4 minutes* Fifth Run Kept at 230° overnight* Thereafter heated about 1° per 3-4 minutes* T°C R-ohms T°C R-ohms 7°C R-ohms 300 285 178 1370 280.5 195 296 275 181.5 1180 284 195 293 24) 186 930 289 230 268.5 225 190 690 291 240 264.5 220 193 550 294 260 261 190 197 .395 297 280 277.5 190 200 305 274 190 203.5 295 272.5 190 206 290 269.5 190 209.5 260 267 190 213 255 264 190 216.5 245 261 190 219.5 245 258 190 223.5 240 253 190 228 240 250 190 232 225 247 190 235 220 244 195 239.5 220 239 200 242 235 237 230 245 220 232 210 249 215 228.5 220 251.5 215 224.5 230 255 210 219 235 2 58 210 - s o - TABLE X SPECIFIC RESISTANCES OF SOBIUM STEARATE H 3*3# Water - First Run Kept at SO overnight* Thereafter heated about 1° per 3-4 minutes. T°C R-ohms T°C R-ohms 125 71*5M 163 3750 127 63*5M 165 3t50 129 49*0H 167 2650 131 42*0M 169 2300 133 46*0M 171 1900 135 42*0M; 173 1670 137 36.5M, 176 14?n 140 30.0M 17S 1150 142 26.0M ISO 1330 144 21*0M ,122 1Q0Q 146 16*5M 484 930 14S 13* 3K iS6 820 154*5 7350 188 775 157 6450 190 760 159 5450 192 710 161 4600 960 Cycles Second Run Kept at room temperature overnighjj. Thereafter heated approximately 1 per 4 minutes* T°C R-ohms 121 84M 123 6 3 1 1 125 6im 127 52B 129 im 131 36.511 133 33.5M 135 33.5M 137 30H 139 26M 141 23. 5M 143 19.0M 145 16.3M 147 12.711 149 10.31 151 9000 TABLE XI SPECIFIC RESISTANCES OF S O D IU M STEARATE I 4./£> W ater - 960 C ycles First Ron Heated rapidly from room temperature to 210°* Thereafter heated about 1 per 3*4 minutes* Second Run Kept at 160° overnight# Thereafter heated about 1° per 3-4 minutes* T°C R-ohms T°C R-ohms T°C R-ohi 210*5 245 162 680 233 200 213 245 165 635 237 195 216.5 255 168*5 620 2/0 195 220 255 171.5 570 243 195 225 255 174 525 246 205 228 255 177 480 252.5 190 232 255 180 395 257 200 239 245 18? 295 263*5 210 242 245 190 255 266 210 246 2/0 193 245 270 210 24S 2/0 198 245 273 210 251*5 230 201 2/0 276*5 210 255 235 204 230 283.5 200 257 245 207 225 287.5 200 260*5 245 210 225 290 205 263.5 245 214*5 225 293 205 268.5 220 218 215 271 220 222 210 275.5 225 225 205 279 220 229 200 281 220 285 225 290 2/0 (C ontinued on N ext Page) " S1(a) - T A B L E XI (Coxxtinued) SPECIFIC R ESISTANCES O F S O D IU M S T E A R A T E I 4*4$ Water - 960 Cycles Third Run Kept at 130° over- Thereafter heated abcut , 1 per 3-4 minutes* Fourth Ron Kept at 100° over night* Then heated about 1° pdr 4 min utes, except toward the end of the run, as noted* Fifth Run Was at room temperature for a few days* Heated to 100° in 1 hour, then about 1° per 3-4 minutes, T°C R-ohms _o_ T C R-ohms T°C R-ohms 136 1160 101 560M 103 450M 139*5 1120 102 485M 105 370M ' 142.5 1080 103 445M 107 300M 145 1040 104 390M 109 280M 143.5 1150 105 36011 111 240M 149 1100 107 305H 113 200M 152 1120 109 255M 115 180M 153 1010 HI 20 OM 116 127M 157 940 113 160M 117 142M 160.5; 875 115 138M 119 82M 164 820 119 138M 121 21. 0M 16? 710 12L 17*214 123 20.0M 170 650 123 17.2M 124 20.QH 173*5 575 125 16.6M 125 18.3M 176 530 127 14*2M 126 17*9M 179 470 129 11.4M 127 15.714 182 415 131 9000 128 14* 5M 185*5 345 132 9200)Readings 129 12.1M 188.5 300 133 8700)15 min- 130 10.8M 192 270 )utes 131 9100 195*5 260 )apart. 132 8600 199 260 133 8200 202 240 132.5 8600)0ne 134 7700 20 5.5 230 )hour 135 7100 )after 136 6700 )132° 137 6350 )reading. 138 6050 140 5450 136 5900)20 142 4600 )hours 144 3700 )later 146 3050 148.5 2400 151 1950 (Continued on Next Page) TABLEXI (C ontinued) SPECIFIC RESISTANCES OF SODIUM STEARATE I 4.4$ Water - 966 Cycles Fifth Run (Continued) Was at room temperature for a few days* Heated to 100 in 1 hour, then . about 1° — . - - — w 7 - - . - - . . per 3-4 minutes T°C fr-ohms 153 1680 155 1420 157 1240 159 1070 161 975 163 840 165 740 167 650 169 580 171 515 173 450 175 395 178 360 -J>Z- T A B L E XII SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E J 6.5% Water - 960 C ycles First Run Second Run ' Kept; at 100° overnight. Heated approximately 1 per 4 minutes, Thereafter heated'about - starting from room, temperature. 1°„per 2 minutes. T ° C R-ohms T ° Q R-ohms T ° C R-ohms 46 448M in 7600 105 2150 47 373M , n3 7200 107 2060 48 3I0M 115 6500 109 1950 49 310M n7 5450 111 1820 50 300M 119 4600 113 1660 51 215M la 2250 114 1590 52 186M 123 1750 n5 1500 53 164M 125 i hif) V 1 n? 1300 55 134M , 127 1340 119 noo 57 104M 129 1120 120 1020 59 89.5M 331 895 121 910 61 67.0M 133 775 122 745 63 55 .OM ' 135 730 123 635 65 48.5M 137 680 125 480 67 43.5M 139 635 128 395 69 36.5M 141 575 129 390 n 31.5M 143 525 130 375 73 27 .OM 145 455 131 355 75 23*5M 147 410 133 320 77 21. OM 149 380 135 305 79 19.OM 152 330 138 285 81 17.OM 153 305 140 260 83 15*5M 154 290 141 245 85 14.0M 155 285 144 220 87 13. 2M 156 275 145 ao 89 12. AM 157 275 146 200 91 11.5M 159.5 285 148 185 93 11. OM 161 275 150 175 95 10.5M 162 255 152 155 97 10.AM 163 245 154 145 99 10. AM 164 240 156 135 101 10.2M 165 225 158 127 103 9750 167 ao 160 123 105 9400 168 190 162 127 107 8600 170 155 164 127 109 8600 172 155 174 155 T A B L E X III SPECIFIC RESISTANCES OF SODIUM STEARATE K 12*8$ Water - 960 Cycles i ,,__ First Run ~ Second Run Heated approximtely Kept at 80° overnight* " Then Heated about 1° per 4 niiriutes, starting per 3-5 minutes, from room temperature. T°C R-ohms T°C , R-phins T°C R-ohms 45 10.5M 82 1380 137 45 47 10i4M 84*5 noo 140 44 m.5 9100 87 1070 142 44 50 8850 89 990 144 44 52 8400 91 925 146 , 48 53.5 10.7M 93 800 148 39 95*5 625 157 36 97.5 525 159 36 99*5 455 161 36 101*5 420 163 36 103.5 385 165 34 105.5 355 167 33 108 315 169 ' 33 no 275 171 32 113 190 173 33 ms 130 176 36 n7 108 178 36 ms 102 180 36 120.5 58 182 36 123 57 184 36 125 55 186 36 127 51 188 36 129 51 190 36 131 49 192 36 135 / | 8 (Continued on Next Page) -5 3 & - T A B L E X III (Continued) SPECIFIC R ESISTANCES O F S O D IU M S T E A R A T E K 12 ♦S# Water - 960 Cycles Third Run Heated approximately 1° per 3-4 minutes> starting from room temperature T°C R-ohms T°C R-ohms 37 10.6M : 95 430 39 9500 97 360 41 8800 99 320 43 8300 101 275 45 7850 103 260 47 7300 105 240 50 6650 107 250 53 6850 109 215 55 7050 111 190 57 7050 113 167 59 6950 115 148 61 6900 117 105 63 6600 119 84 65 6100 121 53 67 5700 123 48 69 4550 125 48 71 4000 127 48 73 3350 129 46 75 2750 131 45 77 2200 133 43 79 ' 1850 135 42 81 1270 137 42 83 850 139 ■ 42 85 685 141 40 87 660 143 39 89 600 145 39 91 560 147 38 93 500 149 36 151 38 - 5 1 ! - I»I0‘ T 5-«05 2' 10*- 10' S* I 0 ‘ 2^9 -I F/g.XL 5 o f Nl j S-t>- A. 0.0°/o Hi O 9 6 0 G>cle^ C D F " • r S -f V < J rv o StCO^oi ri/K V • T~ K. i rA v » -» ix O '?* I 0 ‘ I * \0* r G J 5» ioJr V * C l _ 2* I03F-- 25 5 M 0 J'" 5 * I 0 ‘ to Q □ 0 £78°-2f^ O o G 2«I0‘ I 0 ‘ '40 c t S O 2 60 4 70 ( e * n pa.f^ f ure G* 280 290 .500 -O f - 5 5 - 10 5* 10 6 2*\qS (-IQ5 S'* I04 *2* \0< u t 7) ~u “I * 10 4 '- C {5-I03 u _ T ) 2.-I03 ‘I0J — S*»0* 2* «0* I* 1 0 2 □ □ □ F ^ .Y H S p e c i f i c f ^ e a u t ^»\ o f M * i f r B 0 . 5 io Ha 0 4 2 0 C y c l e s Q F t r 5 f Y tj C c o o l i n ^ ) O 5 » c o n / r u n • T K » e ci IT */ l<\ ( C 0 O I I A } ( s « f i \ f f i U I d i e i p o i n t s 0 / T l i t 4 t ^ f o r J'W /, e o f c t j Y i i y in. . « ^ a □ 2 4 6 < ’- 3 0 27S-* 4 ? □ O O r: O V o GG a Q n d O •• *0*0 CDO*B J L J 200 2 /0 2 2 0 230 24-0 2 5 0 200 2 7 0 2 3 0 2 9 0 3 0 0 3 1 0 Te m pfl.i'c71 o ^C, - 5 4 - IMO6 --- 6-105 — ^-|04 ' — M O * — 5-10* — 2*10* — h lO4 — S*i03 — o < u a_ < /? 2* I0 3 — I A I Q - 3- ~ 5>I0* — 2 -.I O A — l* /O '2 — 120 $ o G O * P r 5 • iz u r S p ecific R *51 s « - \ o * X of N /j6tr- C 1 . 0 % H 2 0 9 6 0 Cycles F i r s t r v v\ A 5 e t o n J ► 'w k i E l T F I ^ J V < J v \ O Fou.rU u ia • FiMk l^toe/ points A# d A * a Ao Are A □ A 0 C t c # 4 O tm \ t t a J 4 o tr • i * k e O f ’ c / d r i t 1 ^ 3 *'a p 4 • ^ / Z d ^ -7 # 140 f 60 lao 200 2< iO 240 260 2 6 ° 300 T e rflt Jr e $ C E . 320 - 5 7 - I * to! 5« 10* 2 * 10 o -£ M O* o •i c r j ^2‘I03 0. C D I ' )03 5*»0‘ 2 < I Q 3 |H O '1 iS4°- 9 A A °a A A A * # □ . Q •s Q O F/J. I K Sp e c ific . R t J i j .o^ N a i o t n D 2 0 % H* 0 4 2 0 C / c / e .s G1 P i ^ 5 t run. ( c o o l i n g ) / A 5 e .c c > r ic l ^ u n T~ n o n ( c o o li a ^ ) * Poi/nin r'urv Pi U . r u n . ( " O * v \ e t jlC u l((e c l p o i i° i j O rn i t-t e d / o k ^*l<{ o < * clarity in op /, , 2 /2-10 G07 24-0-11 260-12 »40 |60 ISO 200 220 24-0 260 2SO JOO Te m pe*"d t u °C. 020 58- h 1 0 * r 5* 10' 2*10* }x |0 5 S'lQ4 F.y x . -Spc.c-/C|C Re5|jtjnt«i Wj5tt • 1 3 2 - 1 4 0 G ♦ O o 2.A < y f /o s o 2*10 ; m o 4 Q C Q o 20 actfc » ~ H a O 9 6 Q C y c l e s 0 run A 5 ft C O r\ ei IT U ✓ X CD T~ U i f' u r\ O F? ^ < T ir l\ r u n • Pi f 4 k_ ruin. ( 5 orvic t- a b u Isi. e« / |3i?t*n4j o irv ii^ te j fo v .s a Ua o-f- cla«r>4y 1 in ^ir< 3 p tv i* n g) p » -e it jo w s poi n ' t . □. 1 8 0 - 1 6 0 5* 10 * Q a_ C O M a V a 0 A 2 * 10* I* 10’ fxlO* ? <36°-15 & a 2 0 4 - 1 7 2 6 4 ° - 1 8 2>»l0 I0‘ too 120 14-0 160 180 2 0 0 220^ 2 4 0 2 6 0 2 7 0 3 0 0 T e Inn p G I T 4 4 oir*i C . W 10s S*!01 2*10 J > £M0 o ( d > • » $5 *10 cc -2*|03 C O 10^ 2- I O'1 180°- 19 A A A Et's • X T p t o i f i c R e i i s t i i t e s o f W <3 S f v- F 2 .5 % Hu 0 A 2Q Cycles □ F i r -5 I v u n ( c o o ( m ^ ) A S eco » \< i rurv O ~T U . i k-J v o n (cOol)*g) * Pot, r I L \ o Mtve 2 GO -21 1*10^ J L 120 /4-0 160 180 aOO_ 2 2 0 2 4 0 . 2 6 0 2 6 0 3 0 0 32.0 . p e i °C . d T O p t c i f \ S' O \ kOI-S ' * ' 1 o - 10' 5 * 1 O b ' 10' 5*10* ^ ^o°-2 6 fa) iv 2 .* I 0 2 M O * o: » 1 6 -2 6 O o cto % I 40 - 2 Q ? \ i • f;9 .s h i S p e - M . c R e i i i t d ‘ i c e i o ( N M S - i r I 4 . 4 % H^O 9 6 0 C^cle-s F,r*t / \ S e c - o » \J /wv^ C D T F r J * r u w \ O F o u r ir \j r \ • F , v- \j \r\_ ( S o /v\ e i J I 4eJ po.^ts OivxitteJ -(or > S cJke o ( * 5"^I03 cu CO -o # . 2 0 k r s &iietr jzveviovS ^ read i n g. 2 - I0 3 I* 10- 5* I0: 2* \0Z 1 6 .3 - 2 9 u D • i 1 ’ ^ a a MO* I GO 12 0 (4.0 1 6 0 ( 6 0 2 0 0 2 2 0 Ta v a - * » v 't . -240 2 60 2.QO 300 •iccfic R e ^ i f i c j ^ c e — Ok r v v ^ 1 * 10' 5«I0- 2-10- 10 a % “ 0 Q a £ 1 9 • X1Y S pee/ fit fR e .S « S 5 O - f N j itt' J 6 . 5 % N j O □ Fi v'.i 4 - K u n. O S . c on J vun ( S o m « p o i n Oi'ni 4-ie<J o 4 clarity |H ^ ) v S' 10* 2* 10* 1*10 □ □ a □ 0 1 0 0 - 3 0 1 Z 0 - 3 I P □ t%Q a Q 5' 10* 0 □ c_ < n 2 MO3 1*10’ 5*10^ 2 ' / 0 ‘ I 0 2 o D O O p o □ O 0 0 0 G a O % G O 1 6 0 - 3 3 < 7 0 - 3 4 \ / 0 0 '' V 0 % % o 9 !2S°-32 O 00 GO O 40 60 BO lOO 120 Te. rr> p e. .6 58.7 6 0 .5 B-ohms 95M 95M 20M 78M 71.5M 64. 5M 5 7 .OM 50. 5M 4 3 .5M 39. OM 3 4 .5M 31 .OM 28. OM 2 4 . 7M 2X.3M 1 8 . 9M - 9 7 - (TABLE 3X1 BISISTAUCES OP SODIUM STEABATE T I n i t i a l W ater 0 on t e n t - 3«< P i n a l Water Content - 3 .7 3fo I n i t i a l Gauge P r e s s u r e - 3000 lb s* P in a l Gauge P r e s s u r e - 250Q l b s . H e a tin g B a te - 2° p e r £0 m inu tes Measurements a t 415 c y c le s T°0 B-ohms 29*8 28OM 31.8- 275M 33.9 265M 35.4 260M 37.2 2 50 M 39.7 235 M 4 1 .3 225M 43.4 208 M 45.6 192M 4 7 .7 178 M 50.0 1 6 0 M 51.8 1 4 8 M 53.9 1 2 4 M 55.9 1 1 4 M 57*9 102 M 6 0 .1 8 9 M 6 2.0 8 0 M Tj SBOT 2 X II BISISITANCES O P SODIUM STEARATE U I n i t i a l Water- Content - 3 .5 0 $ Final. Water: Content - 3 .3 1 $ I n i t i a l Gauge P re s some - 5000 15) s.. F in a l Gauge P r e s s u r e - 4000 ID s. H eating H ate - 2° p e r l / 2 hours Measuremotit s a t 415 c y c le s T°G H-*ohms 35*5 l t 222M 3 7 .5 l t 172M 40 .0 1 , 0 22M 41.3 952M 43*3 872M 4 3 .3 830 M 45.9 700M 4 8 .0 620 M 50.0 600M 51.8 550M 54.0 430M 56.0 370M 58.1 280M - 9 9 - TABLE X X III BES3BTAHCES OF SODIUM ST1ABATE V I n i t i a l Water C out a it - 1 3 . 2 $ Final* Water C ontent - 4*0$ P r e s s u r e H is to r y - At room te m p e r a tu re , a p r e s s u r e o f 5000 pounds was a p p l i e d , and r e l e a s e d a f t e r a few m in u te s • The c y c le was r e p e a te d a b o u t s i x tim e s d u rin g 30 m inutes# A f t e r r a i s i n g th e p r e s s u r e to 5000 pounds a g a in , i t dropped to 3000 pounds i n 2 hours# The sample was h e a te d to 30#4°Cf and d u rin g th e c o u rse of th e n e x t h a lf - h o u r p r e s s u r e was r e l e a s e d and r e - a p p l i e d s e v e r a l dozen tim e s , to v a lu e s ra n g in g from 2000-5000 pounds. P re s s u re to 3000 pounds was th e n a p p lie d , and th e system allo w ed to s ta n d f o r 40 hours a t room te m p e ra tu re . P re s s u r e was th e n a p p lie d to s e v e r a l thousand pounds and r e l e a s e d , and th e p ro c e s s re p e a te d s e v e r a l tim e s. Then a p r e s s u r e s u f f i c i e n t t o g iv e a r e a c t i o n on th e pumping l e v e r o f th e C arver p r e s s — b u t n o t to show on th e gauge— was a p p l i e d , and m easure ments made as t a b u l a t e d below . H e a tin g B ate - 3° p e r 1 /2 h o u r. Measurements a t 415 c y c l e s . T°G B-ohms T°C B-ohms 24 3550 54.5 1450 27 3230 57.0 1350 30.3 2900 60 .0 1 2 2 0 33.1 2680 63.3 1090 3 6 .0 2480 6 6 . 8 980 39.0 2270 6 9 .1 890 4 2 .0 2 1 0 0 73.0 795 4 4 .5 2 0 0 0 76.6 720 4 6 .8 1830 80 .0 650 50.5 1670 8 3.6 600 - 1 0 0 - TABLE XXIV BESISTAUCES OP SOLIUM STEABATE W I n i t i a l W ^ter C ontent - 13*2$ ' P in a l Water Content - 3# 6 $ P r e s s u r e H is to r y - P r e s s u r e was a p p l i e d to 2500 pounds, and r e - a p p l i e d to t h a t v a lu e whenever i t f e l l below 2 0 0 0 pounds d u rin g th e f i r s t ru n . T his was n e c e s s a ry f i v e tim e s. H e a tin g was th en d is c o n ti n u e d , and f i f t e e n hours l a t e r th e p r e s s u r e , which had f a l l e n to below th e l i m i t o f the g a u g e w a s , r a i s e d t o 3000 pounds. L u rin g the second r u n , th e p r e s s u r e was r a i s e d to 3000 pounds when i t f e l l below 2500 pounds. This was n e c e s s a ry e ig h t times* H e atin g H ate - a b o u t 2° p e r 20 m inutes f o r b o th ru n s . M easurements a t 415 c y c l e s . P i r s t n Second Bun T C B-ohms f u B-ohms T C B-ohms T C B-ohms 25 3 7 . 7M 53.4 34.0M 2 0 217M 56.0 32 *5M 27 5K5M 55.8 26. 6 M 23 271M 58.2 2 5 .1M 29 60. 9M 57.7 2 3 .1M 26 2 6 2 .5M 61.0 2 0 .3M 31 6 5 .9M 6 0 .5 17 .OM 29 234M 63 .0 1 6 . 7M 33.2 6 9 . 9M 6 3.2 13. 2M 32.5 21.3M 6 5 .2 1 3 .7M 35 .1 7 6 .6M 6 5 .5 10. 5M 35*0 1 7 7 .5M 6 8 . 0 1 0 . 5M 37.1 7 6 .6M 6 8 .5 7800: 3 8 .0 1 6 2 .5M 70.5 8600 4 0.0 8 1 .6M . 71.0 6400 39 .5 1 4 2 *2M 73.0 6750 4 2.1 7 7 . 6 M 74.0 530 0 4 1 .0 1 2 4 .6M 76 .5 5750 4 4 .5 6 8 . 7M 7 6 .2 4600 4 3 .2 1 0 1 .5M 79.5 4990 46*6 59. 5M 78.3 4200 4 5 .2 8 4 .OM 82.2 4380 49.4 5 0 .4M 81*0 3900 4 8 .2 59.5M 85 .0 3990 51.2 41.0M 83.2 3600 4 8 .2 59. 5M 8 8 . 0 3620 51.0 51 *0M 90.2 3450 53.2 4 1 .OM 94.0 3210 ^$01 - T A B L E X X V SUMMARY OF CONDUCTIMETRIC RESULTS WITH SODIUM STEARATE-WATER SYSTEMS IN PLUNGER CELLS Data In TafctLe XVI x v n XVIII IX XX XXI XXII Water Content Before Ai&er Rim Run 0.4& 0.74* 0.43 1.06 0.98 1.10 0.93 3.47 3.40 3.60 3.73 3.50 3.3L XXIII 13.2 4.0 XXIV 13.2 3.6 Temperatures of "Breaks” ~ iii the ”LRTW curves 4 .... : 1 * ' 77°, 83°„ 89° 52 Additional Observations 56°, 66°, 72° 51°, 73° 52° 52 48°, 52° 51°, 69° 50°, 71° Definite flattening off of the ”LRTt t curve at 95°. The ‘ ’ break1 1 noted is doubtful. Thd “break1 ’ at 56° is a discontinuous*- one. The ’ ’ break” noted is discontinuous The’ ’ break” noted is discontinuous • * ■ The two temperatures noted represent the' beginning and end of a ”hump” in the ”LRT” curve. (These samples had long (and varied, but different (pressure histories before (the runs, as shown in (Tables XXIII and XXIV * That is, there are discontinuities in the LRT curves at these temperatures. -102- 24 tu b e w i t h a drop o f w a te r a t 47°G. B . D. Yold a l s o r e p o r ts th e r e - f o r m a tio n o f a sm a ll amount o f a lp h a i n a c a l o r im e te r c e l l a f t e r h e a tin g above 52° and c o o lin g to room te m p e ra tu re . I t i s th e w r i t e r ' s o p in io n t h a t? (1) G e lls o f the ty p e d e s c r ib e d , w ith p o s s ib l y r a d i c a l m o d if ic a tio n s , co u ld be used to o b ta in im p o rta n t c o n d u c tim e tr ic d a ta on soap-^water system s; and ( 2 ) a stu d y d i r e c t e d a t th e e f f e c t s of p re s s u re on o th e r p r o p e r t i e s o f such system s could w e l l le a d to*new and s i g n i f i c a n t d is c o v e r ie s * - 1 0 3 - CHAPTER V COmUCTIYITIES OP THE SODIUM STEARATE - W ATER SYSTEM: IP THE MIDDLE SOAP AHD SOAP BO ILER1S HEAT SOAP REGIONS * . The b o u n d a rie s o f th e tw o-phase r e g io n c o n n e c tin g th e i s l a n d phases of m iddle soap and soap b o i l e r *s n e a t soap 2 sr a r e i m p e r f e c tl y known* S e a le d " p a r a l l e l - w i r e c e l l s were i n d i c a t e d f o r a c o n d u c tim e tric s tu d y in t h i s r e g io n , s in c e p re v io u s ex p erien ce (C h ap ter IV) had prov en th e inadequacy o f s e a l i n g a ff o r d e d by th e " p r e s s u r e ” c e l l s a t th e te m p e ra tu re s and c o m p o sitio n s o f th e b o u n d a rie s under c o n s i d e r a t i o n . Whether i t i s p o s s ib le f o r such a s tu d y to e s t a b l i s h the above-m entioned phase b o u n d a rie s depends on th e r e l a t i v e c o n d u c t i v i t i e s o f the two phases* These c cm due t i v i t i e s w ere determ in ed a s d e s c rib e d below* A* E xp erim ental • Two system s o f sodium s t e a r a t e w ith medium p e r c e n ta g e s o f w a te r (2 8 .7 $ and 6 9 .3 $) were p re p a re d and homogenized in " p a r a l l e l - w i r e " c e l l s in a manner s im il a r to t h a t d e s c rib e d i n C h ap ter I I , ex cep t t h a t g la s s rod s were n o t n e c e s s a r y b e cau se o f th e low er te m p e ra tu re s under i n v e s t i g a t i o n . S e v e ra l a tte m p ts to homogenize th e f i r s t sample r e s u l t e d i n blowm-up c e l l s b e fo re t h e tem p eratu re of ho m ogenization, a b o u t 280°c f o r t h i s w a te r c o n te n t. F i n a l l y th e sample was s u c c e s s f u l l y homogenized b y adding - 1 0 4 - a weighed amount o f a 1 3 .5 $ sam ple, p r e v io u s ly homogenized i n a n o th e r tu b e , to s u f f i c i e n t w a te r i n a c e l l l i k e C ell A (C h ap ter IY) and hom ogenizing in the u su al f a s h i o n . The 69 .3 $ w a te r sample was homogenized j u s t below 200°C w ith o u t • m ishap, in an o r d in a r y c e l l w ith tu n g s te n e l e c t r o d e s , as d e s c r ib e d i n C hapter I I . The c e l l c o n s t a n t s were 2 . 1 0 and 1.32 r e s p e c t i v e l y , and a l l r e s i s t a n c e m easurem ent^ which were made a t 960 c y c l e s , were reduced to s p e c i f i c r e s i s t a n c e s . Buns w ere made by h e a tin g in th e oven d e s c rib e d i n Chapter I I . T em peratures w ere measured w ith a c a l i b r a t e d therm om eter r e a d in g to o .l° C . The r e s u l t s a re ta b u l a t e d in T ables XXVI and XXVII, and p l o t t e d on th e customary LET axes i n F ig u re s XVII and X V III. B. B e s u lts above 80°C. At e q u ilib riu m above 90° the 2 8 .7 $ w a ter sample i s known to be soap b o i l e r * s n e a t so a p , and above 80° th e 6 9 .3 $ w a te r sam ple, m iddle so a p ; and i t was f o r t h i s re a so n t h a t th e s e c o m p o sitio n s were c h o sen , and th e sam ples r e f e r r e d to a s "Kn and U MI T r e s p e c t i v e l y . Whereas Sample N showed th e s o f t e n in g and c l e a r i n g a s s o c i a t e d w ith th e form a t i o n o f n e a t soap a t 89°Cat th e to p o f th e sam ple, the p ro c e ss was n o t com plete aro und th e bottom a t th e e l e c t r o d e s o u n t i l 1 1 1 C. No re a s o n a b le e x p la n a tio n f o r t h i s b e h a v io r i s a p p a re n t t o t h e w r i t e r , s in c e f r a c t i o n a t i o n o f t h i s dense sample seems im probable, and t h e absence of s ta n d in g - /O S- T A B L E XXVI SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E M 6 9 .3 $ Water - 9&0 C ycles F irst Rian Heated about 1° per 5-6 minutes from room temperature• Second Run Heated about 1° per 5-6 minutes from room temperature. T°C R-ohms T°C B-ohms T°C 32.5 700 4i.o 790 103 34.5 675 43.5 730 160 36.5 666 47*0 685 38.5 670 49.0 660 40.5 623 51.© 650 42.5 585 53*0 635 44.5 565 56.0 630 46.5 575 58.5 585 48.5 550 61*0 540 50.5 540 63.0 540 52.5 520 65.5 540 54.5 510 67.0 515 56.5 500 69.0 515 59.5 460 71.0 450 60.5 450 73.0 375 62.5 460 74.0 225 65.5 465 67.5 460 69.5 445 71.5 425 73.5 300 74.5 215 75.5 158 77*0 117 79.0 71 80.0 62 50 82.5 42 84.5 37 86.0 37 87.5 37 Third Run Other observations made with good electrode- contact at higher tempertures R-ohms 29 33 - /O fc - T A B L E XXVII SPECIFIC RESISTANCES O F S O D IU M S T E A R A T E N I 28*7? Water - 960 Cycles First Run , „ o Heated about 1 per 3 minutes from room Second Run Heated about 1° per 5-6 minutes from room Third Run Heated about 1° per 5-6 minutes from room temperature temperature -temperature T°C R-ohms T°C - R-ohms T°C R-ohms 73 2300 28.5 5400 41.0 3980 79 1200 30.5 5130 43.5 3640 83 785 32.5 4970 47.0 3250 86 250 343 4710 49.0 3010 89 220 36.5 4500 51.0 2930 93 141 38.5 4290 53.0 2780 95 131 40.5 4080 56.0 2930 97 105 42.5 3850 58.5 3040 101 78 44*5 3670 61.0 3170 104 60 46.5 3400 65.0 3120 108 50 48.5 3190 67.0 2990 in 45 5o;5 3080 69.0 2830 n5 45 52*5 2880 71.0 2500 ll9 39 54.5 2930 73.0 2200 123 37 55 *5 3010 74.0 1980 127 37 56.5 3060 155 32 57.5 3140 170 32 58.5 3190 59:5 3250^ 60.5 3350 62.5 3250 65.5 3190 67:5 3140 69.5 2930 71.5 2570 73.5 2200 74.5 1990 75.5 1830 77.0 1560 79.0 1310 80.0 noo 81.0 940 82.5 710 84.5 445 86.0 260 87.5 215 o T V , K o i \ > o o o Q O p ri° i ? o C b % o It o O 0= G G O O. GG o G o > 6 > a o» G G / • / / O -«g- J : O • C /9 " D (6 N f v > 3) □ r- £ L -* CD • 5“ 03 < * > - f t o * ~ 0 ' * > n I « • * T 5 f * f n * 0 0 c ^ % — - < f If i. V t + & - / 0 O G 0 -J 1 O k»n j MO* — 5* IO 3 —' 2 ‘tO3 — MO3 — ^ * J 5' 1 0 — « y o c 'i Z ' \ o * — w - j « a. 'O MO* — 5*10' — 2 *1 0 ' _ MO* _ 20 5 2 ' 6 6 D O O. fO « g « ? eS £3 8 F«9 • • x yFi T ic R e n i I j v \ t « J , o f N 2 3 .7 % M^O 9 6 0 C ' y u l . J r~ i f* iv s i C 3 S e - t o i/ v J v o *\ * T - F v r i ^ O v\ ( S ouv\e t d ia u 13 i e J ^>9 1 * 1^ v o tv\ t {-L e-4 f o / ~s«j K e o 4 - i/i gv'dpki'a^) % □ 1 1 2 0 Q f 03 □ 0 4 0 60 do io o Tew\ ptiTdt//^ 120 J4-0 °C. 160 »ao - 1 0 9 - tem p era tu re g r a d i e n t s i n th e oven has heen dem onstrated p r e v i o u s ly in C hapter I I , page 3 0 . Sample M shows th e o o expected b r e a k i n t h e LBT curve a t 83 C, w i t h i n 3 C of th e l i t e r a t u r e v a l u e . D uring a n o th e r run (not shown i n th e Tables), Sample M showed v e ry h ig h 'a n d e r r a t i c v a lu e s o f r e s i s t a n c e u n t i l 160°C. D uring th e h e a tin g to t h a t tem p era tu re many b u b b le s . su rro unded th e e l e c t r o d e s * The b u b b le s th en d isa p p e a re d f o r a few seconds, re -fo rm e d a g a in , and t h i s e r r a t i c b e h a v io r p e r s i s t e d . Changes o f r e s i s t a n c e c o r r e l a t e d w ith bubble fo rm a tio n and d is a p p e a ra n c e . C ooling the sample r a p i d l y to room tem p era tu re by ..'removing i t from the oven in to th e room allow ed the sub.seq.uent " f i r s t " r u n . In an e f f o r t t o e s t a b l i s h th e s o a p - b o i l e r Ts n e at so a p -s u p e rn e a t soap b oundary, a tte m p ts were made t o m easure the r e s i s t a n c e s of sample K above 180°. These were u n su c c e ss f u l b ecause o f foam ing and th e e v o lu tio n o f b u b b les from th e e l e c t r o d e s • In s p i t e of t h e s e d i f f i c u l t i e s i t i s p o s s ib le to give an answ er to th e main purpose o f t h i s p a r t o f th e i n v e s t i g a t i o n , t h a t i s , to determ in e th e r e l a t i v e c o n d u c t i v i t i e s o f n e a t and middle s o a p . These seem t o b e i d e n t i c a l a t above 120°C and p ro b a b ly lower* w ith t h e v a lu e o f j u s t over 30 ohms f o r th e s p e c i f i c r e s i s t a n c e in th e ra n g e 120°C - 160°C, and w ith a sm all te m p e ra tu re c o e f f i c i e n t . Thus i t would seem th a t an a tte m p t to determ ine th e b o u n d a rie s o f th e tw o-phase r e g io n betw een soap b o i l e r ' s n e a t soap and m iddle soap by a - 1 1 0 - o o n d u c trim e tric method would he unsuccessful*. I t i s q u i te s i g n i f i c a n t t h a t a 1 2 .8 $ w a te r sample (Sample K, C hapter IV) has a 36 ohm s p e c i f i c r e s i s t a n c e ah ore 140°C, w ith a sm a ll te m p e ra tu re c o e f f i c i e n t t h e r e a f t e r ; t h i s o b s e rv a tio n coupled w ith th e r e s u l t s above makes i t a s t r o n g presum p tion t h a t above T and in th e v range o f a t l e a s t 13-70$ water* th e s p e c i f i c r e s i s t a n c e may be in d ep e n d en t o f w a te r c o m p o s itio n . Phase I m p lic a tio n s a t Lower T em p eratu res. The r a t h e r i n t e r e s t i n g "hump" i n th e LPT curve t h a t a p p e a rs in th e 1 2 .8 $ sample (Sample K, C hapter IV) a t 50°- 60°C re a p p e a rs a t 5 2 °- 6 6 °C i n sample N* and to a l e s s e r degree a t 60° - 72°C in sample M * b u t a t w id e ly d i f f e r i n g valu es* 600Q, 3000* an d 450 ohms r e s p e c t i v e l y . B oth t h e b e g in n in g s and t h e p e ak s o f th e "humps" suggest phase changes* E x te n sio n s to t h e l e f t o f the e u te e to id fL a ts co n n ectin g i s o t r o p i c s o l u t i o n to m iddle soap* and middle soap to soap b o i l e r * s n e a t so ap , as diagrammed below , p r e d i c t 76° and 82°C, X s o t l r o b i c Liquid, 5oap Boiler's Comji&sitio* - Wei^fct percent MdStr -112- b u t i t i s e v id e n t t h a t f u r t h e r eon d u c t im e tric work i n th e r e g i o n under c o n s i d e r a tio n sh o u ld prove to be o f c o n s id e ra b le a i d in c le a rin g , some- o f i t s p r e s e n t p e rp le x in g problem s. SUMMABY - 1 1 4 - E l e c t r i c a l c o n d a c t i v i t i e s of a n hyd ro us, pure sodium p a lm i ta te an d s t e a r a t e , and of c o n c e n tr a te d system s o f th e l a t t e r in w a te r, were measured a s f u n c t i o n s of tem p e r a t u r e and w ater c o n te n t. Measurements were made w ith an a l t e r n a t i n g c u r r e n t W heatstone B rid g e ; th e sou rce of c u r r e n t was an a u d i o - o s c i l l a t o r o f v a r i a b l e fre q u e n c y , and th e n u l l - p o i n t i n d i c a t o r a vacuum tube a m p l i f i e r i n c o r p o r a t in g an " e l e c t r i c - e y e ” tu b e . Eor anhydrous sodium p a lm i ta te in a s e a le d g la s s c e l l w i t h p latin u m w ire s as e l e c t r o d e s , s e v e r a l im p o rta n t f a c t s were e s t a b l i s h e d . ( l ) As th e te m p e ra tu re was r a i s e d conductance was f i r s t m easurable a t 239° (a t a v a lu e of about 1 0 ~ 6 mho); ( 2 ) "b re a k s" i n th e s lo p e s of th e l o g a rith m of r e s i s t a n c e v s . te m p e ra tu re (IRT) c u rv e s o c cu rred s u b s e q u e n tly a t 256° and 295°C; (3) a d d itio n s o f l e s s t h a n 1% w a ter to th e soap low ered q u ite m arkedly th e te m p e ra tu re a t which conductance was f i r s t m easurable; and ( 4 ) w ith in r e a s o n a b le l i m i t s , th e same r e s i s t a n c e - te m p e ra tu re v alues were o b ta in e d upon h e a tin g and c o o lin g . Item s ( l) and (3) showed t h a t th e c e l l s and e q u ip ment used were s u i t a b l e f o r stu d y in g c o n c e n tr a te d system s of so ap i n w a te r , p a r t i c u l a r l y a t h ig h er te m p e ra tu re s , b u t a l s o a t low er te m p e ra tu re s a f t e r a d d it i o n s of sm a ll p e rc e n ta g e s of w a te r . Item s (2) and (4) f u r t h e r showed t h a t d a ta o b tain ed in su c h s t u d i e s cou ld be used f o r d e te rm in a tio n s of phase chang es, s in c e 239°, 256° and $95° - 1 1 5 - a g re e w e ll w ith p r e v i o u s ly e s t a b l i s h e d phase t r a n s i t i o n s a t .237°, 253°, and 296°, r e s p e c t i v e l y . C o n d u c tiv ity measurements were made on e lev en sam ples of sodium s t e a r a t e w ith w a te r c o n te n ts ra n g in g from 0,i0 to 1 2 ,8 $ , The c e l l s used c o n s is te d of p a r a l l e l Kovar or tu n g ste n w ire s s e a le d i n to t h e b o tto m s-o f tu b e s ' of '.iPyrex g l a s s e s w ith th e p ro p e r c o e f f i c i e n t s o f expan sion* A f t e r a d d it i o n s of w eighed amounts of soap and w a te r , th e c e l l s w ere s e a le d , and th e c o n te n ts homogenized by h e a t in g them t:o t h e te m p e ra tu re of fo rm a tio n of th e i s o t r o p ic l i q u i d , above about 290;0C f o r th e s e sam ples. In a s e r i e s of e x p lo r a to r y exp erim en ts i t was shown t h a t , a t r a t e s o f heating- f a s t e r than 1 ° p e r 2 or 3 m in u te s, " b r e a k s 11 i n th e LET c u rv e s o ccu rred a t h ig h er te m p e ra tu re s th a n th o se o b ta in e d fo r slo w er r a t e s of h e a t in g . Because of t h i s f a c t and th e p o s s i b i l i t y of u n d e rc o o lin g , most o f th e runs were made a s the te m p e ra tu re in c r e a s e d about 1 ° p e r 3 or 4 m in u te s. The te m p e ra tu re s of th e " b re a k s ” , r a t h e r th a n th e . a b s o l u te v a lu e s of th e s p e c i f i c r e s i s t a n c e s , were used f o r most of th e i n t e r p r e t a t i o n s in t h e r e p o r t . O ften the a b s o lu te v a lu e f o r ‘th e s p e c i f i c r e s i s t a n c e of a given sample a t a giv en te m p e ra tu re v a rie d c o n s id e r a b ly from run to ru n , but in g e n e r a l the la c k of a b so lu te r e p r o d u c i b i l i t y d id not a f f e c t the te m p e ra tu re s a t which th e " b r e a k s ” a p p ea re d i n the LET c u rv e s. F a c to r s w hich may have a f f e c t e d - 1 1 6 - the r e p r o d u c i b i l i t y o f th e a b s o l u te v a lu e s o f r e s i s t a n c e s were c o n s id e re d and d is c u s s e d . The tem peratu re o f th e phase change from su ^ n e a t to n e a t soap f o r th e anhydrous sample has been e s t a b l i s h e d p r e v io u s ly a t E57°G by d i l a t o m e t r i c and h o t-w ire m ethods. A sharp, "break" in th e CRT curve a t E55°C a g re e s w e ll w ith th e tem p era tu re of t h a t t r a n s i t i o n , This f a c t , to g e th e r w ith th e s i m i l a r r e s u l t s o b ta in e d f o r anhydrous sodium p a lm i ta te , made i t p o s s ib l e to p o s t u l a t e t h a t a b r e a k in an LRT curve c o rresp o n d ed to a change in phase. The "b rea k s" o b ta in e d on th e LRT c u rv e s of the e le v e n sodium s t e a r a t e sam ples w ere c l a s s i f i e d and ta b u l a t e d , and th e p o in ts above 1 0 0 °C p l o t t e d on a com po sitio n v s . te m p e ra tu re diagram . P o in ts from l i t e r a t u r e so u rc e s wereaLso in c o r p o r a te d . The n a tu r e of the v a rio u s " b r e a k s ," t h e i r a p p ea ra n c e, changes, and d isa p p e a ra n c e s as f u n c tio n s of w a te r c o n te n t and te m p e ra tu re , com parative c o n d u c t i v i t i e s o f c e r t a i n p h a ses, and th e a p p l i c a b i l i t y of the phase r u l e were a l l c o n s id e re d in some d e t a i l in e s t a b l i s h i n g th e phase b o u n d a r ie s . The diagram d e f i n i t e l y e s t a b l is h e d c e r t a i n phase b o u n d a rie s , and i n d ic a t e d a t l e a s t th e b e g in n in g d i r e c t i o n s f o r o th e r s .: In th e r e g io n of 170° - 300°C, and below 5fo w a te r, th e phase diagram showed "tongues" of th e n e at soap and su b n eat soap ex te n d in g in to about 4fo w a ter c o m p o sitio n . This ty p e of c o n s t r u c t io n has been e s t a b l i s h e d fo r sodium - 1 1 7 9 m y r is ta t e and o th e r soaps by v i s u a l and m icro sco p ic means. The e a r l i e r b e l i e f o f s e v e r a l i n v e s t i g a t o r s t h a t th e se phases p e r s i s t to abou t 1 0 $ w a te r f o r th e sodium s t e a r a t e - w ater system was shown to be i n c o r r e c t . Phase b o u n d a rie s in th e re g io n of 100° - 140°C, - and below 6 $ w a te r, were p r e s e n te d i n acco rd an ce w ith th e f a c t s o b ta in e d and th e i n t e r p r e t a t i o n s of th e c o u rs e s cd T the. LRT c u rv e s . I t was shown t h a t more work i s needed in the l a t t e r re g io n to c l a r i f y th e phase p i c t u r e . A mechanism f o r conductance in th e subneat r e g io n was p re s e n te d , namely, t h a t th e sodium io n s a re th e only con d u ctin g s p e c i e s , and t h a t conductance ta k e s p la c e by t h e i r moving from m ic e lle to m i c e l l e . The mechanism i s based upon i n t e r p r e t a t i o n s of th e fo llo w in g : ( 1 ) th e la c k of frequ ency-d ependence of th e co ndu ctances i n th e range o f 42Q--7800 c y c l e s , th u s e li m in a tin g th e p o s s i b i l i t y of th e c o n t r i b u t i o n of d i p o la r r o t a t i o n , ( 2 ) th e presumed mice l i a r arrangem ent i n the su b n eat phase, (3) t h e un f e a s i b i l i t y of e l e c t r o n conductance, (4) th e a b ru p t changes i n s lo p e s of th e LET curves a t th e su b n e at to n e a t soap t r a n s i t i o n , and (5) the v a lu e s of A and E c a l c u l a t e d from the A rrh en iu s e q u a tio n , a p p li c a b l e to io n ic c o n d u c ta n c e s. The r e l a t i v e cond uctan ces o f sodium s t e a r a t e - w a te r .systems were d eterm in ed in the s o a p - b o i l e r 's n e a t soap and m iddle soap r e g i o n s . r ^ h e 'c o n d u c ta n c e s were measured i n c e l l s of th e type used f o r th e h ig h -te m p e ra tu re - 1 1 8 - meas ureiaents above. Two sam ples of £ 8 .7 $ and 69 .3 $ w ater c o n te n t showed s p e c i f i c r e s i s t a n c e s t h a t w ere i d e n t i c a l w i t h in e x p e rim e n ta l e r r o r from 120° - 160°C. At th e s e te m p e ra tu re s such sam ples a r e knov/n to be i n thei'form of s o a p - b o i l e r 1s neat, soap and m iddle soap* r e s p e c t i v e l y . ^hus i t a p p e a rs t h a t an a ttem p t to d eterm in e c o n d u c tim e tr i- c a l l y th e b o u n d a rie s of th e tw o-phase r e g i o n between them would be u n s u c c e s s f u l. In o rd e r to s tu d y c o n c e n tr a te d sodium s t e a r a t e sytems a t low er te m p e r a tu re s , a c e l l w ith e le c t r o d e s of la r g e a re a was d e s ig n e d . The ceL l consi s te d of a bored m onel-m etal c y l i n d e r , and a t i g h t l y f i t t i n g p lu n g e r. S u i t a b l e i n s u l a t i o n and g a s k e tin g made i t p o s s i b l e to measure r e s i s t a n c e s o f sam ples p laced in th e bore and held i n c o n ta c t w ith th e e le c tr o d e s by p la c in g p r e s s u r e on the p lu n g er by a C arver P r e s s - C onductances were found to be s e n s i t i v e to p re v io u s p r e s s u r e tr e a tm e n t in th e c e l l . P o s s ib le re a so n s fo r t h i s b e h a v io r were d is c u s s e d . At a r b i t r a r y r a t e s o f h e a tin g and a t u n d is tu rb e d p re s su re s* " b re a k s" in th e LPT c u rv e s f o r sam ples o f w a ter c o n te n ts of a few per c en t or l e s s o c cu rred a t te m p e ra tu re s c lo s e to 52° and 71°C, te m p e ra tu re s a t which phase changes for anhydrous and s l i g h t l y hydrous sodium s t e a r a t e have been d e m o n s tra te d . The r e s u l t s a r e o f i n t e r e s t w ith r e f e r e n c e to th e a p p a re n t i r r e v e r s i b i l i t y of the change a t 52°C. BIBLIOGRAPHY - 1 2 0 - BIBLIOGRAPHY 1. R. H Ferg uso n, F. B. R osevear, and H. N o rd sieck, J . Am. Chem. S o c . , 6 £ , 141 (1947)- 2. K. W. G a rd in e r, M. J . B u erg er, and L. B. Sm ith, ' J- P h y s. Chem., 49, 417 (1945)- 3. R . D. Void, J . P h y s. Chem., 49, 3 I 5 (1 945 ). 4. M. H. F i s c h e r , and M. 0. Hooker, The L y o p h ilic C o llo id s . S p r i n g f i e l d , 111 .: C harles C. Thomas Pub. Co. , 1933* 5 . S. S B hatnagar and M. P ra sa d , K o llo id Z e i t s c h r i f t , 34, 13 (19 24). 6 . R. J . Hartman, C o llo id C hem istry. Cambridge, M ass.: Houghton M i f f l i n Co. 1939- Page 3 5 9 . 7 . T. D. D oscher, "A Phase Study o f the Sodium S t e a r a t e - C etane-W ater S ystem ," U npublished d o c to r a l d i s s e r t a t i o n , The U n i v e r s i ty o f S o u th ern C a l i f o r n i a , Los A ngeles, C a l i f o r n i a , 1946. 8 . E d it o r s and E n g in e e rs , The Radio Handbook, E ig h th E d it i o n . S a n ta B a rb a ra , C a li f o r n ia : E d ito r s and E n g in e e rs , L im ite d , 1941. Pp. 514-518. 9 . R. H. M illl^r, R. L. Gar man, and M. E. Droz, E x p erim en tal E l e c t r o n i c s . New York: P r e n t i c e - H a l l and C o ., 1 9 4 3 . P p .269- _ r _ 10. B. Hague, A l t e r n a t i n g C u rren t B ridge Methods. London: Is a a c Pitm an and Sons, L t d . , 1938. Page 8 3 . 11. M. J . Heldman, J . Chem. Ed. 21, 5 5 3 ( 1 9 4 4 ). 12. F. Hovorka and E. E. M endenhall, J . Chem. E d. , 16, 2 3 9 ( I 9 3 9 ). 1 3 . B. Hague, A l t e r n a t i n g C u rren t B ridg e Methods. London: Is a a c Pitm an and Sons, L t d . , 1$38. Page 2 3 8 . 14. B. Hague, A l t e r n a ti n g C u rren t B ridge Methods. London: Is a a c Pitm an and S o n s, L t d ., 1 9 3 8 . P p . 542- 5 5 I . 1 5 . J . D. Heldman, Techniques o f G lass M a n ip u la tio n in S c i e n t i f i c R e s e a r c h . New York; P r e n t I c e - H a l l , I n c ., 1946. 16. S tu p a k o ff L a b o r a to r i e s , I n c . , C atalog o f T e c h n ic a l D ata, S e r ie s KA. P i t t s b u r g h , P enn .: S tu p ak o lT L a b o r a to r ie s , In c . , "1944 • Sheet 1. 4121- 17. N. A. Lange, Handbook of C h e m istry . Sandusky, Ohio: Handbook P u b l i s h e r s , I n c ., 1946. Page I 3 8 4 . 18. L. L. Lyon, 4 1 A R K eological Study o f S o lid Soap System s,*1 U npublished d o c to r a l d i s s e r t a t i o n , th e U n iv e rs ity of S o u th e rn C a l i f o r n i a , Los A ngeles, C a l i f o r n i a , 1944. 1 9 . R. D. Void and M. J . Void, J . Am. Chem. S o c . , 61, 8 0 8 (1939)- 20 J . M. P h i l i p s o n , M, J . Heldman, L. L. Lyon, and R.D.Vold, O il and Soap, 2 1 , 3 I 5 (1944) . 21. J . M. P h ilip s o n , ^ P r e p a r a tio n o f Pure Sodium S t e a r a t e , u U npublished 290L r e p o r t , the U n iv e r s ity of S o uthern C a l i f o r n i a , Los A ngeles, C a l i f o r n i a , 1944. 22. J M. P h ilip s o n , #,P r e p a r a tio n o f Pure S t e a r i c A c id ,w U npublished 290 L r e p o r t , th e U n iv e rs ity o f S outhern C a l i f o r n i a , Los A ngeles, C a l i f o r n i a , 1943- 2 3 . M. J . V oid, JV L Macomber, and R. D. Void, J . Am. Chem.Soc. 6 3 , 168 (1 9 4 1 ). ~ 24. R. D. V oid, J . P h y s. Chem. , 49, 3 I 5 (194 5). 2 5 . J . W. McBain, R. D. V oid, and M. P r i c k , J . P h y s . Chem., 44, 1 0 1 3 ( 1 9 ^ 0 ). 26 R. D. V oid, R. R e iv e re , and J . ¥. McBain, J.Am.Chem.Soc. 6 2 , 1 2 9 3 ( 1 9 4 1 ) . ~ 2 7 . J . W. McBain and ¥ . ¥ Lee, O il and Soap, 20^, 17 ( I 9 4 3 ). 28. J . ¥ . McBain, M. J . Void, and S .A .Jo h n sto n , J.Am.Chem. S o c . 6 3 ., 1000 (1941). 29. R. F u o s s , J . Chem. E d ., 19_, 2 3 I (1942). 30. F S e i t z , The Modern Theory o f S o l i d s . New York: M cGraw-Hill Book Co., I n c . , 1^40. 3 1 . R. M. B a r r e r , D if f u s io n in and th ro u g h S o lid s . Cambridge England: The U n iv e r s ity P r e s s , 1941. 32. M. J . B uerger, L. B. Sm ith, A. de B r e t t e v i l l e , J r ., and F. V. R yer, Pr o c . N atl A cad. S c i . U .S ., 28„, 5 2 6 (1942). 3 3 . N. A. Lange, Handbook of C hem istry. Sandusky, Ohio: Handbook P u b l i s h e r s , I n c ., 1946. Page 460. - 1 2 2 - 34. F. F ra n c is and S. H. P ip e r , J . Chem. Soc. 137 ( 1936). 3 5 . H. H. Ferg uson , F. B. R osevear, and R. C. In d . E ng. Chem., 3 5 , 1005 (194 3). ) _____ S t i llm a n , APPENDICES A PPEN D IX 1 A Method for Determining 2 Independently of " . * 1 ...... their Separate Values Any suitable resistor, Rg, was-placed in a direct current bridge whose other aims were R , R_, and R , arranged in such a ~ ~ 1 2 Box way that R R 3 - JZ R R (1 ) Box 1 R Box 9 was se^ f° r a balance, aid its value noted* Then 1 R and R were interchanged so that 2 1 R. R, _® = (2) Bt. K Box 2 - 2 ~ ..... and the value of IL. ^ obtained at balance* •Boatj It follows algebraically that -126- A P T E N D 3X £ Calculations of the Amounts of Water in the Vapor Phases of the "Wire1 1 Conductance CeUs The calculations that follow show the changes in composition of the condensed phase that may occur under extreme conditions* The ideal gas laws and Raoult1 s law are assumed to hold.* Let: o 3 i 80 s vapor pressure of water in atmospheres at 300 C ♦ 55^ inner diameter of the cell in centimeters •35= weight of the sample in grams L « . length of the tube not filled by solid v s volume of the vapor phase £«■ partial pressure of water = . mol fraction in condensed phase w s weight of water in grams left in the condensed phase m « . weight of water in grams in the gas phase 18 = molecular weight of water 306 = l molecular weight of sodium stearate n s . - % water in the sample *See footnote, page A1 - 1 2 6- ; Thai: w 4 m s. .0035 x n (1 ) w Q ~ 18 - 306it neglecting (2) * *35 - (w> m) 306w 4 6*3> 18 4 305 the term (w 4 m) as not affecting P considerably* -m = PViXffrs . Px 80 x *784 x (*55)2 x 18 x L t nfmPr ; - -- RT ■ - • 82 x 573...... .^/^4* The three equations above can be solved for m in terms of Land n, thus: m / 3 0 6 w ^ - .0073 ^ 306w 4 6.3P The solution for the quadratic equation (4) in ’ ’ m” is m - 1.17n + 6.3 + 2.24L ±\Z(l~.17n + 6.3 + 2.24L)* -4 x 306.x .00785Ln S "3 0 5 “ “ for #iich the root arising when the 4* sign precedes the radic a n d is extraneous ♦ Thus: m = 1.17ft 4 6.3 4 2.24 L-Vfrl.l7n 4 6.3 t 2.24L)* - 9.60 Ln (5) 7 1 2 When n s 1, Lsl, substituting into (5) gives M s:.00072* The composition of the condensed phase is thus jfiffliiffigTS X 100 = 0.8* , instead of the 1*0$ water content originally* - 126- ; Then: w + m s. *0035 x n (1 ) w P x 18 - 306w neglecting (2) w *35 - '(wf.nT 306w * f 6*3> 18 + 'jdS the term (w + m) as not affecting P considerably* irt = PvjK/&=. 0x 80 x *784 x (*55)2 x 18 x L t n-r ; - .. . RT ... . . 82 x 573 . .0073^.(3) The three equations above can be solved for m in terms of Land n, thus: / 306w A m = .0073 1 306w + 6.3/* L » * -0073 1 . <*) The solution for the quadratic equation (4) in HmH is m = l.lTn + 6.3 + 2.24L ± \Z(1.17n + 6.3 + 2.24L)2 -4 x 306.x .00785Ln 2 S 305" " for which the root arising when the + sign precedes the radicand is extraneous* Thus: m = 1.17n 4 6.3 4 2.24 L-m.l7n + 6.3 < ■ 2.2M.)2 - 9.60 Ln (5) 712 W hen n s i , L s i , substituting into (5) gives M s.000?2* The composition of the condensed phase i s thus ■ • ■ 9P 3S , -.00072 x 100 = 0.8$ instead o f the .1*056 water content originally* -1 2 7 - W hen n « 5. L - 1 , the solution for (5) is m - #00251. for which the composition of the condensed phase i s S .* , x 1 0 0 , 4 . # , ' . ' , . instead o f the 5% original water content** In a l l cases, L was kept under one centimeter. Since no sign ifican t results were obtained for any sample of 3$ or more water o above 200 C, i t i s safe to say that for each sample, the composition of the condensed phase did not d iffer by more than a few tenths of a percent from the composition of the prepared sample. U M I Number: DP21739 All rights reserved INFORMATION TO ALL USERS The quaWty of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing p ages, th ese will be noted. Also, if material had to be removed, a note will indicate the deletion. Dissertation Publishing UMI D P21739 Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United S tates Code ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, M l 4 8 1 0 6 -1 .3 4 6

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Asset Metadata

Creator Heldman, Morris J. (author)

Core Title Electrical conductivities of pure soap-water systems

School Graduate School

Degree Doctor of Philosophy

Degree Program Chemistry

Degree Conferral Date 1947-03

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag chemistry, physical,OAI-PMH Harvest

Language English

Contributor Digitized by ProQuest (provenance)

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c17-14785

Unique identifier UC11347940

Identifier DP21739.pdf (filename),usctheses-c17-14785 (legacy record id)

Legacy Identifier DP21739

Dmrecord 14785

Document Type Dissertation

Rights Heldman, Morris J.

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the au...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus, Los Angeles, California 90089, USA