Effect of ionic liquid, 1-octyl-3-methylimidazolium bromide on the thermophysical properties of aqueous d-glucose solutions at 298.15 K

Abstract

Thermophysical properties including densities, viscosities, refractive indices, and molar conductivities for ternary systems containing d-glucose, ionic liquid {1-octyl-3-methylimidazolium bromide ([OMIm]Br)} and water have been measured at 298.15 K. The density and viscosity data have been used to calculate apparent molar volumes, V ϕ , standard partial molar volumes (which equal in value with infinite dilution apparent molar volume), V ϕ 0 , transfer volumes, Δ tr V ϕ 0 , of d-glucose from water to aqueous [OMIm]Br solutions and viscosity B-coefficients. An increase in the values of V ϕ 0 , Δ tr V ϕ 0 and viscosity B-coefficient was observed with increase of ionic liquid concentration. Limiting molar conductivities, Λ 0, and ion association constants, K a, of [OMIm]Br in aqueous d-glucose solutions were estimated from low concentration chemical model (lcCM). Molar refractions, R D, were calculated from refractive index, n D, measurements using Lorentz–Lorenz equation. All of these parameters were discussed in terms of the different solute-solvent interactions occurring between d-glucose and ionic liquid.