CO2-facilitated transport performance of poly(ionic liquids) in supported liquid membranes

Six types of PILs were designed and synthesized by radical polymerization reaction and ion exchange reaction and the H-1 NMR analysis and TG-MS analysis proved the successful procedure and their CO2 permeation properties were evaluated. 1-butyl 3-methylimidazole double trifluoromethane sulfonate ([bmim][Tf2N])-based facilitated transport membrane, with 10 wt% poly([ViE-tIm] Tf2N), showed an excellent CO2 permeability of 920 Barrer, similar to that of the others investigated. PILs were distributed in the SILM using the like dissolves like'' theory to investigate the gas permeation separation performance before and after doping of the PILs in SILM. Owing to the reversible interaction between the CO2 molecules and electropositive PIL chains, this supported ionic liquid membrane selectively transfer CO2 more rapidly. The polymer chains play the role of mobile CO2 carrier in the SLM, and introduce facilitated transport mechanism. This concept may provide a means for fabricating a highly permeable and selective membrane to break through Robeson's upper bound.