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Liquid-liquid equilibria in binary mixtures that contain a room-temperature ionic liquid and an organic solvent-namely, 1,3-dimethylimidazolium methylsulfate, [mmim][CH 3 SO 4 ], or 1-butyl-3methylimidazolium methylsulfate, [bmim][CH 3 SO 4 ] with an aliphatic hydrocarbon (n-pentane, or n-hexane, or n-heptane, or n-octane, or n-decane), or a cyclohydrocarbon (cyclohexane, or cycloheptane), or an aromatic hydrocarbon (benzene, or toluene, or ethylbenzene, or propylbenzene, or o-xylene, or m-xylene, or p-xylene) have been measured at normal pressure by a dynamic method from 270 K to the boiling point of the solvent. Thermophysical basic characterization of pure ionic liquids are presented obtained via differential scanning calorimetry (TG/DSC), temperatures of decomposition and melting, enthalpies of fusion, and enthalpies of glass phase transition. The liquidus curves were predicted by the COSMO-RS method. For [bmim][CH 3 SO 4 ] the COSMO-RS results correspond much better with experiment than those for [mmim][CH 3 SO 4 ]. This can be explained partly by the stronger polarity of [mmim][CH 3 SO 4 ]. The solubilities of [mmim][CH 3 SO 4 ] and [bmim][CH 3 SO 4 ] in alkanes, cycloalkanes and aromatic hydrocarbons decrease with an increase of the molecular weight of the solvent. The differences of the solubilities in o-, m-, and p-xylene are not significant. By increasing the alkyl chain length on the cation, the upper critical solution temperature, UCST decreased in all solvents except in n-alkanes.

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(Solid + liquid) phase equilibria (SLE) for the binary systems, ionic liquid (IL) 1-butyl-3-methylimidazolium thiocyanate [BMIM][SCN] with an alcohol (1-octanol, 1-nonanol, 1-decanol, 1-undecanol, or 1-dodecanol) or water, and (liquid + liquid) phase equilibria (LLE) for the binary systems of [BMIM][SCN] with an alkane (n-hexane, n-heptane, n-octane, n-nonane, or n-decane), benzene, an alkylbenzenes (toluene or ethylbenzene), tetrahydrofuran (THF), cycloalkanes (cyclohexane or cycloheptane), or ethers (di-n-propyl ether, di-n-butyl ether, di-n-pentyl ether, n-butylmethyl ether, tert-butylmethyl ether (MTBE), or tert-butylethyl ether (ETBE)) have been determined at ambient pressure. A dynamic method was used over a broad range of mole fractions and temperatures from 250 to 430 K. In the case of systems IL + alkane, cycloalkane, or ether, the mutual immiscibility with an upper critical solution temperature (UCST) was detected, and in the systems of IL + benzene, alkylbenzene, or THF, the mutual immiscibility with a lower critical solution temperature (LCST) was observed. UV-vis spectroscopy was used to determine the very small compositions of the IL in the n-hexane (about 2 x 10(-5) IL mole fraction), benzene (about 2 x 10(-3) IL mole fraction), cyclohexane (about 2 x 10(-5) IL mole fraction), and THF (about 1.2 x 10(-2) IL mole fraction). For the binary systems containing alcohol, it was noticed that with increasing chain length of an alcohol, the solubility decreases. The basic thermal properties of the pure IL, that is, the glass-transition temperature as well as the heat capacity at the glass-transition temperature, have been measured using a differential scanning microcalorimetry technique (DSC). Decomposition of the IL was detected by the simultaneous TG/DTA experiments. Well-known UNIQUAC, Wilson, and NRTL equations have been used to correlate the experimental SLE data sets for alcohols and water. For the systems containing immiscibility gaps {IL + alkane, benzene, alkylbenzene, cycloalkane, tetrahydrofuran, or ether}, the parameters of the LLE correlation have been derived using the NRTL equation.