High-Performance PEBA2533-Functional MMT Mixed Matrix Membrane Containing High-Speed Facilitated Transport Channels for CO2/N2 Separation

A novel mixed matrix membrane was fabricated by establishing montmorillonite (MMT) functionalized with poly(ethylene glycol) methyl ether (PEG) and aminosilane coupling agents in a PEBA membrane. The functional MMT played multiple roles in enhancing membrane performance. First, the MMT channels could be used as high-speed facilitated transport channels, in which the movable metal cations acted as carriers of CO2 to increase the CO2 permeability. Second, due to mobility of long-chain aminos and reversible reactions between CO2 and amine groups, the functional MMT could actively catch the CO, not passively wait for arrival of CO2, which can facilitate the CO2 transport. At last, PEG consisting of EO groups had excellent affinity for CO2 to enhance the CO2/N-2 selectivity. Thus, the as-prepared functional MMMs exhibited good CO2 permeability and CO2/N-2 selectivity. The functional MMM doped with 40 wt % of MMT-HD702-PEGS000 displayed optimal gas separation with a CO2 permeability of 448.45 Barrer and a CO2/N-2 selectivity of 70.73, surpassing the upper bound lines of the Robeson study of 2008.