Effect of concentration and temperature on apparent molar properties of homologous α-amino acids in aqueous-semicarbazide hydrochloride solutions: A quest on the concept of kosmotropic/chaotropic behaviour of amino acids

Various non-covalent interactions can be scrutinized by the measurement of physical properties. The nature of interactions between drugs and amino acids governs the functionalization process, so a better understanding demands reliable thermophysical data. Keeping this in mind, we report herein the densities, rho, ultrasonic speed, u and viscosities, eta of glycine, l-alanine, l-valine and l-isoleucine in aqueous-semicarbazide hydrochloride (1 wt% and 2 wt% semicarbazide hydrochloride in water) solvents in the temperature range of 293.15-318.15 K at an interval of 5 K and at atmospheric pressure. The density data have been used to calculate the apparent molar properties like V-phi, V-phi degrees and transfer volume, V-phi,V-tr degrees. From the ultrasonic speed data, thermo-acoustical parameters, such as K-s,K-phi, K-s(,phi)degrees and transfer compressibility, K-s,K-phi,K-tr degrees have been evaluated. The viscosity data have been used to calculate Falkenhagen Coefficient, A, Jones-Dole coefficient, B. The hydration numbers, n(H) has also been evaluated. The entropies, Delta S degrees(#) and enthalpies, Delta H degrees(#) activation parameters, Delta mu(1)degrees(#) and Delta mu(2)degrees(#) were also calculated. The co-sphere overlap model was used to interpret the positive V-phi,V-tr degrees values. In addition, the values of V-phi degrees, K-s,K-phi degrees, B and Delta mu(2)degrees(#) have been split into groups' contributions of the amino acids. (C) 2019 Elsevier Ltd.