Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

Activity coefficients at infinite dilution oc1 i P for organic solutes: alkanes, alkenes, and alkyl benzenes in two ionic liquids (ILs) 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP]) and 1-ethyl-3- methylimidazolium dimethylphosphate ([EMIM][DMP]) have been measured by the gas liquid chromatographic method (GLC). The measurements were carried out in the temperature range of (313.15 to 363.15) K. The values of the partial molar excess enthalpies at infinite dilution oHE;1 i P were derived from the temperature dependence of the c1 i values. The entropies oTref SE;1 i P and Gibbs energies oGE;1 i P of organic solutes at a reference temperature Tref = 298.15 K were also calculated from the c1 i values. Selectivity oS1 ij P and capacity ok1 j P at infinite dilution at T = 323.15 K have been determined for hexane (i)/benzene (j), cyclohexane (i)/benzene (j). The results were analyzed in comparison to literature data for other ILs with the [MMIM] and [EMIM] cations. For three isomeric xylenes separation problems, selectivity at T = 323.15 K were also obtained from the c1 i values.