Mixed Micelles Containing Sodium Laurate: Effect of Chain Length, Polar Head Group, and Added Salt

Abstract

Abstract We studied the mixing behavior of binary mixtures of alkylglycosides (CnGly); i.e. n-Octyl β-D-glucopyranoside, n-Decyl β-D-glucopyranoside and n-Decyl β-D-maltoside in combination with sodium laurate (NaL), and N,N-dimethyldodecylamine oxide in combination with NaL. The critical micelle concentration (CMC) data were obtained as functions of the composition based on equilibrium surface tension measurements. The cmc values with and without the addition of salt systems were then analyzed according to the regular solution model developed by Rubingh for mixed micelles. For the added salt systems, we applied Maeda's formulation for ionic/nonionic mixed micelles. For NaL/CnGly mixed systems, an increase in the hydrophilicity of the polar head group of CnGly resulted in a strong interaction between NaL and CnGly. In addition, introducing ionic species to the added salt systems stabilized the nonionic micelles.