Interactions in (l-alanine/l-threonine + aqueous glucose/aqueous sucrose) systems at (298.15–323.15) K

Densities and speeds of sound of (l-alanine + 1 mol L−1 aqueous glucose/1 mol L−1 aqueous sucrose) and (l-threonine + 1 mol L−1 aqueous glucose/1 mol L−1aqueous sucrose) systems have been measured as a function of molal concentration of l-alanine and l-threonine at temperatures: (298.15, 303.15, 308.15, 313.15, 318.15, and 323.15) K. The partial molar volumes, transfer partial molar volumes, partial molar isentropic compressibilities and transfer partial molar isentropic compressibilities have been evaluated using the experimentally measured values of density and speed of sound. The trends of variations of experimental and computed parameters have been discussed in terms of ionic–hydrophilic, hydrophilic–hydrophilic and hydrophilic–hydrophobic interactions operative in the systems.

► The Δtrϕv0 values of l-alanine/l-threonine in 1 mol L−1 aqueous glucose/1 mol L−1 sucrose solution decrease with an increase in temperature.
► The Δtrϕv0 of l-alanine and l-threonine are higher in 1 mol L−1 aqueous sucrose solution than those in 1 mol L−1 aqueous glucose solution.
► The Δtrφk0 values of l-alanine and l-threonine is higher in 1 mol L−1 aqueous sucrose solution than those in 1 mol L−1 aqueous glucose solution.
► The ionic–hydrophilic interactions in l-alanine–aqueous sucrose solution, and ionic–hydrophilic and hydrophilic–hydrophilic interactions in l-threonine–aqueous sucrose solution dominate.