Development of highly efficient solvent extraction separation systems for metal ions utilizing the characteristics of ionic liquids

Okamura, Hiroyuki   

Ionic liquids have unique properties that are quite different from conventional molecular liquids, and have therefore attracted much attention in various fields as novel functional media. When ionic liquids are used as extraction media in solvent extraction, they can also act as "liquid ion exchangers", and it is thus expected to exhibit superior extractability and separability compared with those in conventional organic solvent systems. The author has focused on these characteristics of ionic liquids, and have studied on the extraction separation of metal ions using ionic liquids as extraction media, with the aim of developing highly efficient solvent extraction systems. This article presents the evaluation of the solvent properties of ionic liquids in metal ion extraction, the separation of rare earth metals by the synergistic effect in ionic liquid systems, and the development of a macrocyclic extractant and the structure analysis of the metal complex extracted into the ionic liquid.