JCAP Special Seminar

Room Temperature Ionic Liquids (RTILs) are solvents consisting entirely of ions resembling the ionic melts of metallic salts; however, RTILs are liquids at much lower temperatures. RTILs have high thermal stability, high ionic conductivity, negligible vapor pressure and are non-flammable. Unlike traditional organic media, RTIL's properties may be adjusted via chemical alteration of the cation or anion to produce application specific compounds. Many RTILs are liquids over a wide temperature range with some known melting points as low as -96 °C and some liquid ranges in excess of 300 °C. High coulombic forces constrain the RTIL constituents and thus, the RTILs exert practically no vapor pressure above the liquid surface. These features have led to current investigations of RTILs as alternative media for a variety of applications that use organic solvents. 

This presentation provides an overview of our recent efforts and research directions in the design and synthesis of several new types of functionalized, imidazolium-based RTILs, poly(RTIL)s, and RTIL-based composite materials for use in the area of targeted gas separations. Polymeric versions of ILs have been synthesized and used as membranes for gas separations. In addition to a physical solvent, RTILs might also be incorporated into RTIL polymers or in supported ionic liquid membranes (SILMs) as the selective component. For example, the addition of 20% RTIL into an RTIL polymer increases the permeability ten fold (100 vs. 10 barrer) while maintaining selectivity. Gelled versions exhibit large permeabilities (~ 1000 barrers) as well as CO₂/N₂ selectivities (^~ 30) that outperform many polymer membranes in that application.