Solution Properties of Ternary D-Glucose + 1-Ethyl-3-methylimidazolium Ethyl Sulfate + Water Solutions at 298.15 K

The effect of an ionic liquid, 1-ethyl-3-methylimidazolium ethyl sulfate (EMIm]ESO₄), on the thermophysical properties of aqueous D-glucose solutions including density, viscosity, and electrical conductivity have been investigated at 298.15 K. Using these properties, the apparent molar volumes, V _φ , the viscosity B-coefficients and the molar conductivities, Λ _m, have been computed for the ternary D-glucose + EMIm]ESO₄+water solutions. The V _φ values were used to calculate the standard partial molar volumes, V_f⁰V_{\phi}^{0}, and transfer volumes, D_trV_f⁰\Delta_{\mathrm{tr}}V_{\phi}^{0}, of D-glucose from water to aqueous ionic liquid solutions. These volumetric parameters, for all the solutions studied, are positive and increase monotonically with increasing the concentration of EMIm]ESO₄. These observations have been interpreted in terms of the interactions between D-glucose and ionic liquid in the aqueous solution. The viscosity data were analyzed in terms of the Jones-Dole equation to determine the values of the viscosity B-coefficients. The calculated conductometric parameters, the limiting molar conductivities, Λ ₀, the association constants, K _a, and the Walden products, Λ ₀ η, for EMIm]ESO₄, decrease with increasing concentration of D-glucose. This trend suggests that the ions of an ionic liquid do not have the same hydrodynamic size in the presence of D-glucose molecules (ILs) and consequently provides evidence for the dehydration effect of the ionic liquid in aqueous D-glucose solutions.