The invention includes compositions comprising curable imidazolium-functionalized poly(room-temperature ionic liquid) copolymers and homopolymers. The invention further includes methods of preparing and using the compositions of the invention. The invention further includes novel methods of preparing thin, supported, room-temperature ionic liquid-containing polymeric films on a porous support. In certain embodiments, the methods of the invention avoid the use of a gutter layer, which greatly reduces the overall gas permeance and selectivity of the composite membrane. In other embodiments, the films of the invention have increased gas selectivity and permeance over films prepared using methods described in the prior art.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under grant number DE-AR0000098 awarded by the U.S. Department of Energy and grant number HDTRA1-08-1-0028 awarded by the DOD/DARPA. The government has certain rights in the invention.