Measurements of Activity Coefficients at Infinite Dilution in Solvent Mixtures with Thiocyanate-Based Ionic Liquids Using GLC Technique

摘要

The activity coefficients at infinite dilution, γ_(13)~∞ for 34 solutes-alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, ethers, and ketones-in the ionic liquid 1-butyl-4-methylpyridinium thiocyanate, [BMPy][SCN], and in 1-butyl-1-methylpyrrolidinium thiocyanate, [BMPYR][SCN], were determined by gas-liquid chromatography at the temperature range from 298.15 to 368.15 K. The partial molar excess enthalpies at infinite dilution values, ΔH_l~(E,∞), were calculated from the experimental γ_(13)~∞ values obtained over the temperature range. The selectivities for the n-heptane/benzene, cyclohexane/benzene, and n-heptane/thiophene separation problems were calculated from the γ_(13)~∞. Obtained values were compared to the literature values for the other ionic liquids, NMP, and sulfolane.