Experimental Study of CO2 Effect on O2/N2 Separation Performance of Polydimethylsiloxane

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

Emmanuel O Ogbole - North Carolina A&T State University
Co-Author(s): Jainzhong Lou, North Carolina A & T State University, Greensboro; Shamsuddin Ilias, North Carolina A & T State University, Greensboro

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Gas separation is a very important unit operation in the process industry. Most gases or vapors in their natural forms need purification before they can be used. For separations where ultra-pure and tonnage quantities of gas is required, conventional technologies like cryogenic distillation, swing adsorption, and chemical process are mostly used. But for small or intermediate scale gas separation operation, polymeric membranes offer several benefits over the conventional gas separation technologies. These benefits include operation flexibility, low capital and operating costs, lower energy requirement, and general ease of operation and fabrication.
However, greater implementation of polymeric membranes is hindered by their intrinsic permeability and selectivity limitations. Research related to the development of polymeric membranes with improved gas separation performance focuses on the manipulation of penetrant diffusion and solubility coefficients via systematic modification of the polymer structure, incorporation of fillers, thermal post-treatment, etc.
In this study, the impact of CO2 on gas transport properties of polydimethylsiloxane (PDMS) was investigated. Single gas permeability coefficients O2 and N2 through polydimethylsiloxane (PDMS) films were experimentally measured before and after treating the films with CO2 for 24 hr. The permeability of O2 and N2 through the untreated and CO2-treated films were compared. The O2 and N2 permeability for the CO2-treated films were observed to have a remarkably lower permeability than those of the untreated films. In the treated films, O2 and N2 permeability decreased by 2.5% and 16.9% respectively and the PDMS selectivity of O2 over N2 increased from 2.13 to 2.61. Using CO2 treatment effect offers a new way of enhancing the gas separation performance of rubbery polymer (PDMS) for production of O2 and N2 enriched-air.

Not Submitted

Funder Acknowledgement(s): NSF

Faculty Advisor: Jainzhong Lou, lou@ncat.edu

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