In situ creation of crystalline channels in ultrathin network polymer membranes for pressurized H ₂ /CO ₂ separation

Ordered channels provide an excellent foundation for creating gas-selective pathways in polymeric membranes that endure pressurized and high-temperature conditions. Herein, we present a competitive-reaction interfacial polymerization (CRIP) approach to in situ creation of crystalline channels in ultrathin network polymer membranes, which allows the crystalline segments to attach to the amorphous polymer network tightly. The separation performances of the membrane were regulated by controlling the reaction parameters, and the microstructure was characterized systematically. The as-prepared membrane exhibited an extraordinary mixed H₂/CO₂ selectivity of 85 with a H₂ permeance of 184 gas permeation units under 11 bar and 150°C. Membranes show outstanding resistance to high pressures and temperatures, which offers high attractiveness for H₂ production and CO₂ capture.