An imidazolium-based ionene blended with crosslinked PEO as a novel polymer membrane for selective CO2 separation

Abstract

A novel imidazolium-based ionene was mixed with a di(ethylene glycol) diacrylate that was subsequently photocrosslinked to form a blend membrane useful for CO2/N-2 gas separation. The crosslinked poly(ethylene oxide) (PEO) offered a mechanically stable matrix with a high CO2 affinity. The ionene loading affected both the structure and CO2 separation performance of the blend membranes as demonstrated by varying the ionene content in three levels, 1:1, 2:1, and 3:1 (ionene:crosslinker) by weight. The CO2 solubility of the membrane dramatically increased with the ionene loading level, and a high CO2/N-2 permselectivity of 33.5 was obtained for the [3II-cPEO][TFSI]. The imidazolium-based ionene blend membranes prepared with crosslinked PEO (II-cPEO) also displayed good thermal and mechanical stability.