Room temperature ionic liquids (RTILs) have been touted as useful alternatives to volatile organic solvents, partly because they have low vapor pressures, are not flammable, and generally have much lower toxicity to their organic counterparts. One limitation of RTILs is their immiscibility with water, which limits certain reactions and studies.

Yuki Kohno and Hiroyuki Ohno, Tokyo University of Agriculture and Technology, Japan, have demonstrated that a phase change of the lower critical solution temperature type is possible. This allows liquid-liquid binary mixtures containing an ionic liquid and water to form a single phase. The discovery could allow the systems to be used as novel solvents for studies of biopolymers where a phase change might be exploited to separate proteins, for instance. Similarly, such mixtures might be investigated as polyelectrolytes for the preparation of functional gels and thin films.

• Ionic liquid/water mixtures: from hostility to conciliation,
  Y. Kohno, H. Ohno,
  Chem. Commun. 2012.
  DOI: 10.1039/C2CC31638B