Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

Densities and viscosities of aqueous solutions of R-amino acids (glycine, DL-alanine, DL-R-amino-n-butyric acid, DL-R-valine, and DL-R-leucine) + sodium caprylate have been measured as a function of the concentrations of amino acid and sodium caprylate at 298.15 K. These data have been used to calculate apparent molar volumes and viscosity B coefficients of the amino acids. The standard partial molar volume and standard volumes of transfer have been determined for the amino acids. It has been shown that values of standard partial molar volume and the B coefficient vary linearly with the increasing number of carbon atoms in the alkyl chain of the amino acids, and they were split into contributions from the zwitterionic end group (NH3 +, COO-) and CH2 groups of the amino acids. From the volumetric data, it is suggested that the amino acids are solubilized in the palisade layer of sodium caprylate micelles. The viscosity properties have been interpreted in light of the solute-solvent interactions in aqueous media.