Activity coefficients at infinite dilution and physicochemical properties for organic solutes and water in the ionic liquid 1-(2-methoxyethyl)-1- methylpyrrolidinium trifluorotris(perfluoroethyl)phosphate

Abstract

This work presents new data of activity coefficients at infinite dilution, γ∞ of different organic solutes and water in the 1-(2-methoxyethyl)-1-methylpyrrolidinium trifluorotris(perfluoroethyl)phosphate ionic liquid. Values of γ∞ were determined for 62 solutes, including alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, esters, 1-nitropropane, butanal, acetonitrile and water by inverse gas chromatography over the temperature range from (318.15 to 368.15) K. The basic thermodynamic functions, namely partial molar excess Gibbs energies, ΔGE,∞1, enthalpies, ΔHE,∞1 and entropies, ΔSE,∞1 at infinite dilution were calculated from the experimental γ∞ values obtained over the temperature range. Additionally the gas-liquid partition coefficients, KL were determined. Experimental values of gas-liquid partition coefficients were used to determine the coefficients in the Abraham solvation parameter model (LFER). Results are compared to previously investigated ionic liquids with the same cations or anions. The selectivities and capacities at infinite dilution for alkanes/thiophene extraction problems were calculated from experimental γ∞ values to verify the possibility of investigated ionic liquid as an entrainer in liquid-liquid extraction. © 2013 Elsevier Ltd. All rights reserved.