High gas permselectivity in ZIF‐302/polyimide self‐consistent mixed‐matrix membrane

Abstract

ABSTRACT Zeolitic imidazolate framework‐302 (ZIF‐302) was incorporated within a polyimide (PI) matrix in order to develop a highly selective and permeable mixed‐matrix membrane (MMM) for gas separation processes. On the basis of varying fabrication procedures, two different MMMs were formed: a dense MMM (ZIF‐302/d‐PI) and a spongy, self‐consistent MMM (ZIF‐302/s‐PI). The spongy membrane was shown to have self‐consistent and disconnected pores with a reduction in overall membrane density. For ZIF‐302/d‐PI, a 1.2–1.5‐fold increase in the permeability of H 2 , O 2 , N 2 , CO 2 , and CH 4 was observed when compared with the pure d‐PI membrane. For ZIF‐302/s‐PI, even better improvements (up to 19‐fold higher) in permeance were achieved with negligible effects on selectivity. The gas transport mechanism was then analyzed and showed a considerable enhancement of diffusion coefficients for ZIF‐302/s‐PI, while ideal gas pair selectivities for CO 2 /N 2 , H 2 /CH 4 , and H 2 /N 2 were found to be 24.8, 42.3, and 62.6, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48513.