Abstract: An inverse gas chromatographic method has been used to measure the solubility parameter of the dicationic ionic liquid, 1,10-bis(3-methylimidazolium-1-yl)decane hexafluorophosphate ［C10(MIM)2］［PF6］2, at the absolute temperatures from 343.15 K to 363.15 K. The test probe solvents were n-octane, n-dodecane, n-tetradecane, and n-hexadecane. The specific retention volumes of the solvents (V0g), the molar enthalpy of sorption (ΔHS1), the partial molar enthalpy of mixing at infinite dilution (ΔH∞1), the molar enthalpy of vaporization (ΔHv), the activity coefficients at infinite dilution (γ∞12), Flory-Huggins interaction parameters (χ∞12) between ［C10(MIM)2］［PF6］2 and probe solvents were obtained. The solubility parameter (δ2) of ［C10(MIM)2］［PF6］2 was determined as 15.01 (J\5cm~3)1/2, which was of great importance to the study of the solution behavior and application for ionic liquid.

Key words: activity coefficients at infinite dilution, dicationic ionic liquid , solubility parameters, inverse gas chromatography