Dehydration effect of ionic liquid, 1-pentyl-3-methylimidazolium bromide, on the aqueous d-glucose solutions: Thermodynamic study

Effect of an ionic liquid, 1-pentyl-3-methylimidazolium bromide ([PnMIm]Br), on the solution behavior of aqueous D-glucose solutions has been investigated. For this purpose, various thermophysical properties such as density, viscosity, electrical conductivity, and refractive index have been measured at T = 298.15 K. Thermophysical parameters including standard partial molar volume (Vϕ0) and corresponding transfer volume (ΔtrVϕ0), hydration number (nHnH), viscosity B  -coefficient, free energy of activation per mole of the solvent (Δμ10≠) and the solute (Δμ20≠), ion association constant (Ka), and molar refraction at infinite dilution (RD0) have been calculated using the measured experimental data. The obtained parameters have been used to understand various mixing effects of components due to the solute–cosolute interactions. It was observed that the values of transfer volume and viscosity B-coefficient increase with increasing the concentration of [PnMIm]Br. The results suggest that ionic liquid has a dehydration effect on D-glucose in water. This opinion is confirmed by the observed depletion in the values of hydration number and ion association constant.

► Structure making ability of ionic liquid on the aqueous D-glucose solutions.
► Predominance of hydrophilic–ionic interactions between D-glucose and ionic liquid.
► Dehydration effect of ionic liquid, [PnMIm]Br on the aqueous D-glucose solutions.