Ionic Liquid–Based Liquid Membranes in Separation Technique

Recent progress on liquid separations using ionic liquid membranes, such as emulsion and supported liquid membranes, and pseudo–emulsion membrane strip dispersion containing ionic liquids, has been briefly reviewed. Regarding supported liquid membranes, a number of attempts to improve the membrane stability involving application of ionic liquids to the impregnated liquid were conducted. Researches relating to metal ions, hydrocarbons and organic acids permeation through supported ionic liquid membranes and polymer inclusion membranes were viewed, and the permeation mechanism was discussed. Polymer inclusion membranes were found to be an excellent alternative in terms of higher membrane stability and comparable permeation rate, in comparison to that of supported ionic liquid membranes in the case of liquid separation.