- Development of advanced mixed matrix membranes for gas separations.
- Development of high performance zeolitic imidazolate frameworks (ZIFs) for gas/vapor separations.
- Adsorption and diffusion in microporous crystalline materials.
Low-molecular-weight olefins are consumed as feedstocks to produce a variety of significant chemicals. Membrane separations have been emerging as more energy-efficient alternatives to fractional distillation to enrich olefin from olefin/paraffin mixtures.
Mixed matrix membranes, formed by dispersing molecular sieve particles in polymer matrices, are promising approaches for gas/vapor separations. The selection of molecular sieves and polymer matrices is crucial to fabrication of mixed matrix membranes with intact polymer-sieve adhesion and favorable gas transport properties. Efforts have been made by us to evaluate the performance of several microporous molecular sieves in terms of their propylene/propane adsorption and molecular sieving properties. Mixed matrix dense films were prepared with selected molecular sieves and polymers, showing propylene/propane selectivities that were of practical importance.
The hollow fiber geometry combing high surface area/volume ratio and ease of module formation is the most practical geometry for industrial gas separations. With optimized molecular sieves and polymers from dense film studies, we are going to pursue the spinning of asymmetric mixed matrix hollow fiber membranes by incorporating molecular sieve particles in their selective dense skin layers.Recent Publications
- C. Zhang, Y. Dai, J.R. Johnson, O. Karvan & W.J. Koros, "High performance ZIF-8/6FDA-DAM mixed matrix membrane for propylene/propane separations." Journal of Membrane Science, 389 (2012), p. 34. DOI: 10.1016/j.memsci.2011.10.003
- C. Zhang & W.J. Koros, "High performance ZIF/Polyimide Mixed Matrix Membrane for Separation of Propylene/Propane," 24th Georgia Tech ChBE Annual Graduate Student Research Symposium. Atlanta, GA. March 2012.