(149a) Mixed-Matrix Membranes Based on Polymers of Intrinsic Microporosity and Metal-Organic Frameworks for Gas Separation Applications
The concept of potentially enhancing both permeability and selectivity of polymeric membranes by embedding microporous carbon, zeolites or metal-organic frameworks (MOFs) in a mechanically strong polymer matrix by forming mixed-matrix membranes (MMMs) has been one of the many research areas pioneered by Bill Koros and co-workers. Inspired by his groundbreaking work on 6FDA-DAM polyimide/ZIF-8 MMMs for propylene/propane separation1 our group developed MMMs using hydroxyl-functionalized polyimides of intrinsic microporosity that served as ideal polymer matrices due to their excellent compatibility with ZIF-8. Here, we report the fabrication and exceptional pure- and mixed-gas gas permeation properties of PIM-PI-based MMMs containing ZIF-8 loadings ranging from 20% to 65% by weight. The MMM membranes were tested with a 50:50 C3H6/C3H8 feed mixture at pressures up to 7 bar (p/psat ~0.8). Exceptional C3H6/C3H8 mixed-gas selectivities ranging from 20 at 30% loading to 30 at 65% loading were achieved. Furthermore, minimal onset of plasticization was observed, highlighting the strong potential of PIM-6FDA-OH/ZIF-8 mixed-matrix membranes for C3H6/C3H8 separations.
1. Chen Zhang, Ying Dai, Justin R. Johnson, Oguz Karvan, William J. Koros, âHigh performance ZIF-8/6FDA-DAM mixed matrix membrane for propylene/propane separationsâ, J. Membr. Sci. 389 (2012) 34-42.