ZIF-based water-stable mixed-matrix membranes for effective CO2 separation from humid flue gas

Water stable mixed-matrix membranes (MMMs) were developed to help control global warming by capturing and sequestrating carbon dioxide (CO2) from humid flue gas originated from burning of fossil fuels. MMMs of different compositions were prepared by doping glassy polymer Ultrason((R)) S 6010 (US) with nanocrystals of zeolitic imidazolate frameworks (ZIF-302) in varying degrees. A solution-casting technique was used to fabricate various MMMs to optimize their CO2 capturing performance from both dry and wet gases. The prepared composite membranes indicated enhanced filler-polymer interfacial adhesion, consistent distribution of nanofiller, and thermally stable matrix configuration. CO2 permeability of the membranes was enhanced as demonstrated by gas sorption and single gas permeation tests carried out under dry and moist circumstances. As compared to neat Ultrason((R)) membrane, CO2 permeability and expected CO2/N-2 permselectivity of the mixed membrane doped with 40g/g ZIF-302 nanocrystals were significantly enhanced. In contrast to the majority of previously reported membranes, key features of fabricated MMMs include their structural stability under humid conditions coupled with better and unaffected gas separation performance.