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MOLECULAR MODELING OF SILICON CARBIDE NANOPOROUS MEMBRANES
AND TRANSPORT AND ADSORPTION OF GASEOUS MIXTURES THEREIN
by
Nafiseh Rajabbeigi
A Dissertation Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(CHEMICAL ENGINEERING)
December 2009
Copyright 2009 Nafiseh Rajabbeigi
Object Description
| Title | Molecular modeling of silicon carbide nanoporous membranes and transport and adsorption of gaseous mixtures therein |
| Author | Rajabbeigi, Nafiseh |
| Author email | rajabbei@usc.edu; n_rajabbeigi@yahoo.com |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Chemical Engineering |
| School | Viterbi School of Engineering |
| Date defended/completed | 2009-08-17 |
| Date submitted | 2009 |
| Restricted until | Unrestricted |
| Date published | 2009-09-28 |
| Advisor (committee chair) | Sahimi, Muhammad |
| Advisor (committee member) |
Tsotsis, Theodore T. Mak, Chi Ho |
| Abstract | The goal of this work is to study transport of gas mixtures through nanoporous membranes especially silicon carbide membranes.; In the first stage of this research, molecular dynamics simulation has been performed to study the transport and separation of gas mixtures through a single nanopore. Transport of binary mixtures of n-alkane and CO2 in carbon nanopores and the effect of various parameters such as temperature, pressure, pore size and length of the system on the separation were investigated. For generating n-alkanes chains Configurational-bias Monte Carlo method was used and combined with the dual control volume grand canonical molecular dynamics simulation.; The next phase of this work is to study the transport of gas mixtures through nanoporous silicon carbide membranes using molecular dynamics simulation. We develop a new model for nanoporous materials and inorganic membranes, the pore space of which consists of interconnected pores of irregular shapes and sizes. The model is based on the Voronoi tessellation of the atomistic structure of the crystalline or amorphous materials, of which the membrane is made. It generates three-dimensional molecular pore networks with pore-size distributions (PSD) that resemble those of real inorganic nanoporous materials. In addition to being interconnected and having irregular shapes and distributed sizes, the pores also have rough internal surface, which is what one may expect to exist in most real nanoporous materials. To test the validity of the model, we utilize it to model adsorption in three distinct silicon-carbide (SiC) membranes. Equilibrium molecular dynamics simulations are employed to compute adsorption isotherms of nitrogen in the nanoporous SiC membranes. Using at most one adjustable parameter, the simulated isotherms and the experimental data are in very goodagreement.; We also aim to simulate transport properties of our prepared SiC membranes using the feed back that we get from our adsorption simulation. Non-equilibrium molecular dynamics simulations used, in order to study transport and separation of two binary mixtures, namely, H2/CO2 and H2/CH4, and compare the results with the experimental data. The model is demonstrated to provide accurate predictions, in particular for the separation factors of the mixtures, without needing anyadjustable parameter. |
| Keyword | adsorption; molecular dynamics simulation; nanoporous; nanoscale; silicon carbide; transport of gases |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m2620 |
| Contributing entity | University of Southern California |
| Rights | Rajabbeigi, Nafiseh |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | cisadmin@dots.usc.edu |
| Filename | etd-Rajabbeigi-3225 |
| Archival file | uscthesesreloadpub_Volume23/etd-Rajabbeigi-3225.pdf |
Description
| Title | Page 1 |
| Contributing entity | University of Southern California |
| Repository email | cisadmin@dots.usc.edu |
| Full text | MOLECULAR MODELING OF SILICON CARBIDE NANOPOROUS MEMBRANES AND TRANSPORT AND ADSORPTION OF GASEOUS MIXTURES THEREIN by Nafiseh Rajabbeigi A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (CHEMICAL ENGINEERING) December 2009 Copyright 2009 Nafiseh Rajabbeigi |
