Studies on sodium dodecylsulfate in aqueous and in aqueous amino acid solutions: Volumetric and viscometric approaches

Physicochemical properties like density, ultrasound velocity and viscosity of aqueous solutions of glycine and SDS (sodium dodecylsulfate) in 0.1 m aqueous glycine solution as a function of concentration at different temperatures ranging from 293.15 K to 313.15 K have been determined. These data have been used to calculate apparent molar volume, isentropic compressibility and viscosity B-coefficient values of the studied solutions. The viscosity coefficients A and B have been determined from the Jones-Dole equation. The limiting apparent molar volumes (phi(0)(v)) and experimental slopes (S-v) derived from the Masson equations have been interpreted in terms of solute-solute and solute-solvent interactions. From the volumetric and viscometric data, the structural effect of SDS in glycine solution has been discussed. The change in free energy, enthalpy and entropy of activation were calculated using the Nightingale and Benck, and Eyring equations. Glycine in aqueous solution exhibits structure-breaking behaviour. The results were explained in terms of structure making and structure breaking properties. (C) 2013 Elsevier Ltd. All rights reserved.