抄録
Metal–organic frameworks (MOFs) have been recognized as a novel material for gas separation membranes based on their ordered pore structure and adsorption properties. Major problems for developing MOF–based membranes are reducing inter–crystalline defects and elucidation of permeation mechanism. In this study, Cu–BTC and ZIF–8 membranes were developed by counter–diffusion method, which supplies each solutions of the metal salt and the organic ligand from both sides of the porous support. Especially, ZIF–8 membranes with less defects were prepared, and propylene/propane separation based on their small difference in molecular sizes were clarified. ZIF–8 membranes were also prepared via direct growth on a zinc oxide–modified support, and the influence of defects in the polycrystalline selective layer was quantitatively estimated by dividing the permeance into microporous, Knudsen, and viscous flows.
