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

Abstract

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, Vφ, the viscosity B-coefficients and the molar conductivities, Λm, have been computed for the ternary D-glucose + [EMIm]ESO4+water solutions. The Vφ values were used to calculate the standard partial molar volumes, \(V_{\phi}^{0}\), and transfer volumes, \(\Delta_{\mathrm{tr}}V_{\phi}^{0}\), 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, Λ0, the association constants, Ka, and the Walden products, Λ0η, 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.