Activity coefficients at infinite dilution of organic solutes in the ionic liquid PEG-5 cocomonium methylsulfate at T = (313.15, 323.15, 333.15, and 343.15) K: Experimental results and COSMO-RS predictions

作者：Reddy Prashant; Siddiqi M Aslam; Atakan Burak; Diedenhofen Michael; Ramjugernath Deresh^*

来源：Journal of Chemical Thermodynamics, 2013, 58: 322-329.

DOI：10.1016/j.jct.2012.10.024

• Activity coefficient at infinite dilution
• PEG-5 cocomonium methylsulfate
• Ionic liquid
• Gas-liquid chromatography
• Speed of sound
• COSMO-RS

Activity coefficients at infinite dilution gamma(infinity)(13) have been determined for 25 polar and non-polar organic solutes (alkanes, cycloalkanes, alk-1-enes, alk-1-ynes, aromatic compounds, alcohols, and ketones) in the ionic liquid PEG-5 cocomonium methylsulfate with gas-liquid chromatography at four different temperatures, T = (313.15, 323.15, 333.15, and 343.15) K. Packed columns with phase loadings of 0.28 and 0.34 ionic liquid mass fraction in the stationary phase were employed to obtain gamma(infinity)(13) values at each temperature investigated. Speed of sound, density, and refractive index values have also been measured for the pure ionic liquid at P = 0.1 MPa and T = (303.15, 313.15, 323.15, 333.15, and 343.15) K. The uncertainties in the sound speeds, densities, and refractive indices are estimated to be values of 0.9 m . s(-1), 0.00003 g . cm(-3), and 0.00002, respectively. Partial molar excess enthalpies at infinite dilution Delta H-1(E,infinity) were calculated for the solutes from the temperature dependency of the gamma(infinity)(13) values for the temperature range of this study. The uncertainties in the determinations of gamma(infinity)(13) and Delta H-1(E,infinity) values are 5% and 10%, respectively. Selectivity values at infinite dilution S-12(infinity) for hexane/benzene, cyclohexane/benzene, hexane/hex-1-ene, and hexane/ethanol separations have been calculated. These have been compared against values obtained from COSMO-RS predictions.

• 出版日期2013-3