ABSTRACT
Ionic liquids are composed only of ions, and they exist in liquid from over a wide temperature range with no vapor pressure. Ionic liquids, formerly called room temperature organic molten salts, behave as liquids in the absence of an organic solvent. Lowering the melting temperature of salts is not so dif—cult. For example, NaCl is in a molten state above 801°C, but when heteroaromatic ammonium cations are used, chloride salts show a melting temperature below 100°C (Bonhôte et al. 1996). After 2000, an increasing number of studies on the ionic liquids has been found in several scienti—c —elds. Ion-conductive material is a typical example.
