Salting- in effect of deep eutectic solvents on the aqueous solutions of D-glucose by using isopiestic method

Abstract

In this work, the salting-in effect of some deep eutectic solvents (DESs) based on choline chloride on the aqueous solutions of D-glucose using the vapor–liquid equilibrium (VLE) data were investigated. The water activity data were obtained precisely using an improved isopiestic method and correlated with Wilson, e-NRTL, and UNIQUAC models. Also, the Hansen solubility parameters were calculated to predict the selection of appropriate solvent system. The e-NRTL model was employed to calculate activity coefficient, and the Gibbs free energies of transfer of D-glucose from water to aqueous DES solutions. Isoactivity lines of water in all systems show a large positive deviation from the linear isopistical relation (Stokes-Robinson's Zdanovskii law), which is due to the salting-in effect. The results indicate that the salting-in effect is greater in the presence of glycerol based DES and show strong interactions between D-glucose and the DES and is favorable.