Infinite dilution activity coefficients and thermodynamic properties of selected organic solutes and water dissolved in 1, 6-hexanediol

Abstract

The experimental activity coefficients (γ13∞) and gas-to-liquid partition coefficients (KL) at infinite dilution for 34 organic solutes and water were determined in 1.6-hexanediol (HDO) by the gas–liquid chromatography technique (GLC) in the temperature range from (323.15 to 353.15) K. Fundamental thermodynamic functions such as excess partial molar enthalpy (ΔHiE,(∞)), excess partial molar Gibbs energy, (ΔGiE,∞) and entropy, (TrefΔSiE,∞) at infinite dilution were calculated from experimental values of γ13∞. Reported data were discussed in terms of solvent-solute interactions, heat effects and mixing spontaneity. Selectivity (Sij∞) and capacity (kj∞) related to different separation problems were calculated from γ13∞ data and compared to the literature values for selected ionic liquids (ILs), deep eutectic solvents (DESs) and industrial solvents. New data reported in this study suggest that HDO may be proposed as an alternative solvent for the separation of alkanes-pyridine and alkanes-thiophene systems. Furthermore, it was found that adding a hydrogen bond acceptor to HDO enhances its performance as a separation solvent.