Mixed Matrix Membranes Based on Metal–Organic Frameworks with Tunable Pore Size for CO 2 Separation

Two isomorphous MOFs (Ni 2 ( l -asp) 2 bipy and Ni 2 ( l -asp) 2 pz) with different pore sizes were incorporated into poly(ether- block -amide) (Pebax-1657) to prepare the mixed matrix membranes (MMMs) with gas permeation properties for CO 2, H 2, N 2, and CH 4 . Different loading ratios of MOFs with mass percentage from 10% to 30% were studied. Compared with the pure polymer membrane, the as-synthesized two series of MMMs showed improved CO 2 permeability and CO 2 /H 2 selectivity. The highest CO 2 permeation property was achieved by Ni 2 ( l -asp) 2 bipy@Pebax-20 of 120.2 barrers with an enhanced CO 2 /H 2 selectivity of 32.88 compared with 55.85 barrers and 1.729 of the pure polymer membrane, respectively, which makes it a potential candidate for future applications in CO 2 capturing.