Study of solute-solute and solute-solvent interactions of homologous series of some alpha-amino acids in aqueous-D-xylose solutions at different temperatures by using physicochemical methods

摘要

The densities, rho of glycine, L-alanine, L-valine and L-isoleucine in aqueous-D-xylose (2.5% and 5% D-xylose in water, w/w) solvents were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K; and ultrasonic speed, u and viscosities, eta of these solutions were measured at temperatures (298.15, 303.15, 308.15, 313.15 and 318.15) K and at atmospheric pressure. The rho, u and eta values have been used to calculate apparent molar volume, V-phi, limiting apparent molar volume, V degrees(phi), apparent molar compressibility, K-s,K-phi, limiting apparent molar compressibility, K degrees(s,phi) transfer volume, V degrees(phi,tr), transfer compressibility, K degrees(s,phi,tr) and limiting partial molar expansibility, E degrees(phi). The viscosity values have been used to determine Falkenhagen Coefficient, A, Jones-Dole coefficient, B, partial Gibbs energy of activation of viscous flow per mole of solvent, Delta mu degrees(1)# and per mole of solute, Delta mu degrees(2)#. These parameters have been discussed in terms of solute-solute and solute-solvent interactions prevailing in these solutions. The structure making/breaking ability of the amino acids in these solutions is also discussed. In addition, the values of V degrees(phi), K degrees(s,phi), B and Delta mu degrees(2)# have been split into groups' contributions of the amino acids. (C) 2016 Elsevier Ltd.