Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

The (solid + liquid) and (liquid + liquid) phase equilibria for 10 (ionic liquid + water) binary mixtures havebeen determined by a dynamic method at a wide temperature range at atmospheric pressure.The mutual immiscibility with an upper critical solution temperature (UCST) for the binarysystems {4-(2-methoxyethyl)-4-methylmorpholinium trifluorotris(perfluoroethyl)phosphate, or 4-(2-methoxyethyl)-4-methylmorpholinium bis(trifluoromethylsulfonyl)imide, or 1-(2-methoxyethyl)-1-methylpiperidinium trifluorotris(perfluoroethyl)phosphate, or 1-(2-methoxy-ethyl)-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide, or 1-(2-methoxyethyl)-1-methylpyrrolidiniumbis(trifluoromethylsulfonyl)imide, or 4-(2-methoxyethyl)-4-methylpyrrolidinium trifluo-rotris(perfluoroethyl)phosphate (1) + water (2)} were detected. Complete miscibility in the liquidphase, over the whole range of ionic liquid mole fraction, was observed for the binary mixtures con-taining: 1-butyl-1-methylpiperidinium dicyanamide, or 1-butyl-1-methylpyrrolidinium dicyanamide,or 1-butyl-4-methylpyridinium dicyanamide, or 1-butyl-4-methylpyridinium thiocyanate.For the tested binary systems with immiscibility gap the parameters of the LLE correlation have beenderived using the NRTL equation. The (solid + liquid) phase equilibria have been correlated by means ofNRTL, UNIQUAC and Wilson equations and compared to the literature data for different ionic liquids. Theinfluence of the ionic liquid structure on water solubility was discussed.