Sulfonated polyimide/ionic liquid composite membranes for carbon dioxide separation

Ionic liquid (IL)/sulfonated polyimide (SPI) composite membranes exhibit high carbon dioxide (CO2) permeability with good CO2/N2 selectivity. CO2 permeation coefficients (P CO2) are higher than 400 Barrer at 30 °C when the composite membranes include 75 wt% of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide. The IL/SPI composite membranes also exhibits excellent mechanical properties (Young’s modulus 10 MPa) and can be processed into thin and uniform membranes. These characteristics are preferable as CO2 separation membranes.