Some aspects of ionic liquids as diverse and versatile sustainable solvents

In this mini review several particular cases of ionic liquid solution behavior are discussed, namely solutions of ionic liquids with aliphatic alcohols, polyalcohols, arenes, chloromethanes and poly(ethyleneglycol) as well as salting-out and salting-in effects. The presented cases clearly expose ionic liquids as being diverse and versatile sustainable solvents that exhibit flexible phase behavior and, consequently, variable phase diagrams. These can be tuned either by changing the length of the alkyl chain(s) of the ionic liquid's cation (and/or sometimes the anion), or by introducing a different aliphatic nature to the other solution constituent (e.g.; by varying polymer chain length or the number of carbon atoms in chloromethanes). Sometimes, the evolution of the phase diagrams is fine and continuous, showing several consecutive stages, revealing both qualitative and quantitative changes. Finally, the diversity and versatility of ionic liquids are viewed as important features that contribute to their efficiency as tunable solvents or salting media.