This NSF award by the Chemical and Biological Separations program supports work by Professors J. Karl Johnson and Eva Marand at University of Pittsburgh and Virginia Polytechnic Institute and State University, respectively, to study novel methods for separating gaseous mixtures with very high energy efficiency. Current methods for industrial separation of mixed gases is both energy and capital intensive. We propose research to enable the design of novel membranes that selectively transport gases, have high flux, and have low capital and energy costs. The objectives of our proposed work are: (1) construct and test ultra-thin oriented single-walled carbon nanotube (SWNT) asymmetric composite membranes and (2) develop accurate molecular-level models that can elucidate the phenomena governing transport and selectivity of mixed-feed gases in the experimentally produced membranes. These objectives will be accomplished through a unique blend of experiments and atomically detailed modeling. Extensive studies of gas separation membranes indicate that new membrane materials are needed in order to dramatically improve the effectiveness of membrane-based gas separations. Theoretical and experimental studies of carbon nanotubes have indicated that these materials may provide such a breakthrough; these materials are predicted to have both high selectivities and extraordinarily high fluxes for gas transport and represent a fundamentally new class of membrane materials with the potential to allow low-cost, high efficiency separation of gases. We plan to employ a patented method, developed by us, to fabricate defect-free carbon nanotube/polymer composite membranes for experimental transport studies. This method allows us to prepare oriented SWNTs and multi-walled carbon nanotubes on large-area porous supports.
