Crosslinked microporous membrane with dual-function compensation for long-term and efficient CO2 separation

Abatract A polymer of intrinsic microporosity (PIM) membrane that commonly remains both highly permeable and mechanically robust under aggressive CO 2 feeds is still an unmet challenge. Here this work proposes a novel crosslinking strategy with dual-function compensation that simultaneously preserves free volume and enhances CO 2 dissolution for microporous membrane preparation. Amino-functionalized ZIF-8 (ZIF-8-NH 2 ) nanoparticles are dispersed in bromomethylated PIM (PIM-BM) and subsequently thermally crosslinked via Hofmann alkylation. The incorporated ZIF-8-NH 2 therefore acts simultaneously as covalent crosslinking nodes that restrict chain mobility and suppress physical aging/plasticization, and permanent CO 2 -philic pores (0.34 nm) that compensate the free volume loss upon crosslinking network formation. The optimal c-PIM/ZIF-9 wt% membrane exhibits an exceptional CO 2 permeability 6803.53 Barrer as well as CO 2 /N 2 selectivity of 29 with equimolar mixed gas. Meanwhile, the membrane also demonstrates remarkable resistance to both physical aging and plasticization. This work presents a novel strategy that offers a promising avenue for developing high-performance microporous membranes for particle carbon capture.