A Highly Permeable Mixed Matrix Membrane Containing a Vertically Aligned Metal–Organic Framework for CO2 Separation

Delicately regulating the distribution morphology of a filler is an effective strategy to promote the separation performance of mixed matrix membranes (MMMs). Herein, we describe a highly permeable metal–organic framework (MOF)-based MMM comprising vertically aligned ZIF-8 (V-ZIF-8) and polysulfone (PSF). The V-ZIF-8 is distributed uniformly within the PSF matrix. With this unique distribution morphology of ZIF-8, the shortest gas transport pathways are formed in the membrane. Meanwhile, the molecular-sieving pores of ZIF-8 can allow CO 2 to pass through and crowding out N 2 . The obtained V-ZIF-8/PSF membrane shows a high CO 2 permeability of 89.7 Barrer and a CO 2 /N 2 selectivity of 30.0 that is stable over a period of 50 h. The CO 2 permeability is enhanced about 11.8 times than that of the pure PSF membrane. The results prove that the vertically aligned distribution morphology of an MOF in a polymer matrix is an effective method to improve the separation performance of a membrane, providing a new concept for designing more advanced membranes.