Phase behaviour of trihexyl(tetradecyl)phosphonium chloride, nonane and water

Abstract

This research details our investigations into the potential for separating the ionic liquid trihexyl(tetradecyl)phosphonium chloride ([P_{6 6 6 14}]Cl) from nonane using water. A miscible two component mixture of [P_{6 6 6 14}]Cl and straight chain hydrocarbon separates upon addition of water into a three-phase mixture. The phase behaviour for [P_{6 6 6 14}]Cl/water/nonane is presented, showing a stable three-component phase, whereby any additional water or nonane separates into its own immiscible layer. Although this limits the potential use of this system for entirely separating hydrocarbons from this ionic liquid, it has potential for other uses, such as triphasic catalysis.