Solid–Liquid Equilibria of 1-Ethyl-3-methylimidazolium Hexafluorophosphate + Polyols

Abstract

Solid–liquid equilibrium (SLE) data for binary system 1-ethyl-3-methylimidazolium hexafluorophosphate ([EMim][PF6]) + polyols (ethane-1,2-diol, propane-1,2-diol, propane-1,2,3-triol) and ternary systems ([EMim][PF6] + ethane-1,2-diol + propane-1,2-diol, [EMim][PF6] + ethane-1,2-diol + propane-1,2,3-triol, [EMim][PF6] + propane-1,2-diol + propane-1,2,3-triol) have been measured. The results show that the solubilities of [EMim][PF6] in a single solvent decrease with the alkyl chain length and number of hydroxyl groups in polyols. The solubilities of [EMim][PF6] in mixed solvents at the same temperature are in the order of ethane-1,2-diol + propane-1,2-diol > ethane-1,2-diol + propane-1,2,3-triol > propane-1,2-diol + propane-1,2,3-triol. The solid–liquid data for the binary and ternary systems are correlated by the NRTL equation, and the correlation results agree well with the experimental results.