Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

Activity coefficients at infinite dilution (c1 i ) and gas-liquid partition coefficients (KL) for organic solutes: n-alkanes, alkenes, alkyl benzenes, acetonitrile, acetone, tetrahydrofuran, ethyl acetate, and chloromethanes in the ionic liquid (IL) 1-hexyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide ([HMMIM][NTf2]) have been measured by the gas-liquid chromatographic method (GLC) in the temperature range of (313.15 353.15) K. The thermodynamic functions at infinite dilution as partial molar excess enthalpies at infinite dilution (HE;1 i ) were derived from the temperature dependence of the c1 i values. Gibbs energies (GE;1 i ) and entropies (Tref SE;1 i ) of organic solutes in [HMMIM][NTf2] at a reference temperature Tref = 298.15 K were also calculated from the c1 i values. The solubility parameters of the IL [HMMIM][NTf2] were determined by two methods. Selectivity (S1 ij ) and capacity (k1 j ) at infinite dilution at 323.15 K have been determined for n-hexane (i)/benzene (j), cyclohexane (i)/benzene (j). The results were analyzed in comparison to literature data for alkylimidazolium-based ILs with [NTf2] . For three isomeric xylenes separation problems, selectivity at 323.15 K were also obtained from the c1 i values.