Effect of temperature on partial molar volumes and viscosities of aqueous solutions of α-dl-Aminobutyric acid, dl-Norvaline and dl-Norleucine

Abstract

In this work, we present experimental results for partial molar volumes and viscosities of aqueous solutions of α-dl-aminobutyric acid, dl-norvaline and dl-norleucine at 288.15, 293.15, 298.15 and 303.15 K. The thermodynamic behavior of aqueous amino acid solutions is compared with that reported for glycine and α-alanine in water and is discussed in terms of group additivity and electrostriction.

The temperature dependence of the infinite dilution partial molar volumes and the B viscosity coefficients are interpreted in terms of amino acid hydration. According to the usual hydrophobicity criteria, the amino acids considered do not have a hydrophobic character and their behavior is dominated by the polar groups.

Keywords:

• Amino acid
• Hydrophobicity
• Solute–solvent interactions
• Viscosity

Acknowledgments

This work was supported by the Universidad Nacional de Colombia and the Universidad de Córdoba. We would like to express our appreciation to the reviewer for his comments and suggestions for improving the manuscript.