A calorimetric study on interactions of amino acids with sodium dodecylsulfate and dodecyltrimethylammonium bromide in aqueous solutions at 298.15K

Enthalpies of solution and transfer of glycine, L-alanine, L-Valine, L-serine and L-threonine from water to aqueous surfactant (sodium dodecyl sulfate or dodecyltrimethylammonium bromide) solutions have been determined at 298.15 K by isothermal calorimetry. Dehydration and ion-ion interactions are important at low concentrations of the surfactant. Hydrophobic-hydrophobic interactions become primary when the amino acid molecules insert into the hydrophobic tail groups of the micelles. These phenomena can be explained with the hydration co-sphere ovelap model. (C) 2008 Elsevier B.V. All rights reserved.