Investigation of the synergistic effect and the morphology of the binary compound systems with potassium N-lauroyl glycinate

Abstract

Abstract Potassium N-lauroyl glycinate (PLG) is an amino acid surfactant widely used in detergents and has excellent chemical properties. In the present work, PLG was mixed in different molar ratios (α1) with the commonly used amphoteric surfactant lauryl amidopropyl betaine (LAB) or the non-ionic surfactant alkyl glycoside (APG). Subsequently, the surface tension, average hydrodynamic radius and number of micellar aggregates of the individual surfactants and the compound systems were measured using the hanging plate method, dynamic light scattering and fluorescence probe method, respectively, and the corresponding surface activity parameters were calculated. The results show that the binary PLG/LAB and PLG/APG systems exhibit non-ideal behaviour and that there was mutual attraction in the systems. The broad distribution of the micelle radius of the PLG/LAB compound system indicates that there are two types of micelles, namely spherical and rod-shaped in the systems. The distribution of the micelle radius of the PLG/APG compound system decreases to the minimum value at α 1 = 0.5. At α 1 = 0.7 and 0.9, double peaks and a broad distribution were also observed. The number of micelle aggregates in the PLG/LAB and PLG/APG compound systems is less than that of the individual surfactants at the respective mole fractions.