Interactions of Diglycine in Aqueous Saccharide Solutions at Varying Temperatures: A Volumetric,Ultrasonic and Viscometric Study

Densities, viscosities and speeds of sound were measured for ternary mixtures of diglycine (0.05 to 0.30 mol⋅kg⁻¹) in 2, 4 and 6 mass-% aqueous xylose, L(-)arabinose, and D(-)ribose solutions at 288.15, 298.15 and 308.15 K and at atmospheric pressures, using a DSA 5000 instrument. The limiting apparent molar volume, limiting apparent molar adiabatic compressibility and their corresponding slopes were computed using the density and speed of sound data. Corresponding transfer functions have also been determined. The viscosity data have been analyzed on the basis of the Jones-Dole equation. The viscosity B-coefficient and Gibbs energy of activation of viscous flow per mole of solvent and solute have been evaluated. Hydration numbers, pairwise and triplet interaction coefficients have also been evaluated from these data. The variations of these parameters with concentration and temperature clearly suggest the roles of diglycine and saccharides in solute–solvent interactions.