Solvation behaviour and partial molar properties of monosaccharides in aqueous protic ionic liquid solutions

Abstract

The densities, ρ and speeds of sound, u of d(+)-glucose and d(−)-ribose in water and in (0.10, 0.20, 0.30, and 0.40)mol·kg−1 aqueous protic ionic liquid (3-hydroxy propylammonium formate) solutions were measured at temperatures, T=(298.15 to 318.15)K. Infinite dilution standard partial molar volume, V2∞ and standard partial molar isentropic compressibility, Ks,2∞ have been calculated, which were used to evaluate the standard transfer volumes, ΔtV2∞ and ΔtKs,2∞. The ΔtV2∞ and ΔtKs,2∞ values for monosaccharides decrease in the order: d(+)-glucose>d(−)-ribose. The transfer parameters are positive and increase with molalities of ionic liquid (IL) and with temperature. Further, the expansion coefficients, (∂V2∞/∂T)P, its derivative (∂2V2∞/∂T2)P, pair (VAB and KAB) and triplet (VABB and KABB) volumetric interaction coefficients and hydration numbers, Nw have also been calculated and used to discuss the solvation behaviour of monosaccharides. The variation in the taste quality of monosaccharides in the presence of IL has also been studied from apparent massic volume, vϕ and apparent massic isentropic compressibility, Kϕ,m parameters.