ZIF-90/P84 mixed matrix membranes for pervaporation dehydration of isopropanol

By modifying the synthesis route, we have synthesized ZIF-90 nanoparticles with an average particle size of 55nm and embedded them into P84 polymeric membranes with excellent dispersion for the dehydration of isopropanol (IPA)/water mixture via pervaporation. The effects of ZIF-90 loading as well as feed temperature on pervaporation performance of the mixed matrix membranes (MMMs) were systematically investigated. The flux of MMMs increases with increasing ZIF-90 loading due to the enhanced fractional free volume, while the separation factor of water/IPA can be maintained at 5432 when the ZIF-90 loading is less than 20wt%, but reduced to 385 when the ZIF-90 loading is 30wt%. Interestingly, the application of sulfonated polyethersulfone (SPES) as a primer to ZIF-90 nanoparticles before fabricating MMMs consisting of 30wt% ZIF-90 recovers the separation factor without sacrificing the flux. The best MMM showed the separation performance with a flux of 109gm^-2h^-1 and a separation factor of 5668 at 60°C. This encouraging performance suggests a promising future of ZIF-90/P84 composite membranes for the dehydration of IPA via pervaporation process.