Supported ionic liquid membranes and facilitated ionic liquid membranes

Supported Liquid Membranes (SLMs) use porous supports impregnated with a solvent. In SLMs, solute molecules dissolve into the membrane at the feed/membrane interface. The dissolved species diffuse through the membrane and desorb at the opposite membrane surface. The addition of a third mobile chemical or carrier to the solvent that can reversibly bind to the dissolved species enhances the selectivity of the membrane (facilitated transport). Supported Ionic Liquid Membranes (SILMs) have an advantage over SLMs due to the negligible loss through vaporization of Room Temperature Ionic Liquids (RTILs) and the ability to selectively modify the properties of the membrane solvent. Our initial research focus was on the CO2 separation from N-2 using RTILs with and without ionic and neutral doping compounds. Our chapter presents the proof-of-concept of SILMs, the basic principles of FILM development, and discusses future needs for continued development of SILMs and FILMs. Our SILM had a CO2 permeability of 4.6 x 10(-11) Mol/(cm(2) kPa s) with a selectivity over air of 29; these values are competitive with existing membrane materials. The FILMs had a 1.8 improvement in CO2 permeability with a driving force of 4.6 kPa of CO2.