An Electrochemical Viewpoint on Extraction of Ions in Ionic Liquid-Water Two-phase Systems

Abstract

  Recently, extraction of ions by use of ionic liquid-water two-phase systems has been intensively studied. However, the very fact that ionic liquids are salts that consist of cations and anions has been overlooked, except in interpreting the mechanism of the extraction, either in terms of ion-exchange or ion-pair extraction. In such systems, an electrochemical viewpoint is useful to see the fact that the partitioning of the ionic liquid between the ionic liquid-water two-phase system mainly determines the phase-boundary potential between the two phases, and the distribution and extraction of ions, accordingly.