Gas Permeability/Selectivity Studies Through Surface-Treated SiO2-PDMS (Polydimethylsiloxane) Nanocomposite Membranes

Graduate #135
Discipline: Technology and Engineering
Subcategory: Materials Science

Emmanuel Ogbole - North Carolina Agricultural and Technical State University
Co-Author(s): Jianzhong Lou and Shamsuddin Ilias, North Carolina A & T State University, Greensboro, NC

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Membrane-based gas separation has become an important unit operation in the chemical industry for the past three decades. For small and intermediate scale gas separation operations (like O2-enriched air for medical, furnace applications, etc.), polymer membranes offer a number of benefits over other conventional gas separation technologies, such as operation flexibility, low capital and operating costs, lower energy, requirement and, generally ease of operation and fabrication, etc. In this research, the effects of different weight percent incorporation of nano fumed silica (SiO2) into polydimethylsiloxane (PDMS) on the gas permeability and selectivity of the membranes are being studied theoretically and experimentally. Permeabilities of O2, N2, CO2 and CH4 through the mixed matrix membranes (MMMs) are experimentally measured and theoretically predicted using Maxwell, Higuchi, Bruggeman, and Bottcher-Landauer models. Theoretical permeabilities of the MMMs (SiO2-PDMS) using the models predict results in the following order: Maxwell model > Bruggeman model > Bottcher model > Higuchi model. Preliminary results of the experimental permeabilities measurements of O2, N2, CO2 and CH4 at 30psig under room temperature show that there are significant deviations between the measured results and the theoretical models. However, the experimental permeability of measurements of N2 through 10 wt% and 20 wt% SiO2-PDMS show close agreement with Higuchi model. Improved O2/N2 and CO2/CH4 selectivity performance of SiO2-PDMS over neat PDMS from 2.05 to 2.58 and from 3.31 to 3.84 respectively.

Funder Acknowledgement(s): NSF

Faculty Advisor: Jiazhong Lou and Shamsuddin Ilias, lou@ncat.edu

Role: Development of experimental procedure; design of experimental setup; experimental data generation/analysis; research report.