Effects of counter ions on physiochemical properties of linear anionic amino acid surfactants
Date
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
DOI
Abstract
This study focuses on surfactants that contain hydrophobic tails based upon undecylenic acid and an amino acid such as alanine, S-aminobutyric acid, Norvaline and Norleucine as a hydrophilic headgroup. For these amino acid-based surfactants, various physical properties such as surface pressure and critical micelle con- centration (CMC) are measured. In addition, thermodynamic parameters associated with micellization such as change in Gibbs free energy and change in entropy are calculated. Because the surfactants’ amino acids’ carboxyl groups are deprotonated at the studied pH, each surfactant is negatively charged; as such, counteri- ons such as 1,2 Diaminopropane, 1,3 Diaminopropane, Ethylenediamine, and Sodium bicarbonate are added to stabilize the solution. The physical and thermodynamic properties for each surfactant are also measured and calculated with respect to each of these counterions. This is part of a broader study examining the physical properties of amino acid-based micelles.