Novel anionic extended surfactant and cationic surfactant mixtures for maximizing synergism (solubilization and adsolubilization) and minimizing precipitation

Abstract

Generally, anionic and cationic surfactant mixtures exhibit desirable properties, but are limited by their tendency to form precipitates. In this research, mixture of anionic extended surfactants and a cationic surfactant have been evaluated for precipitation phase boundaries, surface tension, adsorption, adsolubilization, solubilization, desorption, and surface characterization. The results showed that anionic extended surfactant and cationic surfactant mixtures can greatly increase formulation space (reduce precipitation region) while maintaining synergism, although slightly reduced from conventional anionic-cationic mixtures reported previously. For adsorption study, mixed anionic extended surfactant and cationic surfactant systems can reach plateau adsorption region at lower surfactant concentration than that of the CPC alone, although the maximum adsorption capacity of CPC is not enhanced in our mixed surfactant systems. Moreover, stabilities of these mixed surfactant systems are slightly lower than have the individual surfactant system. However, solubilization and adsolubilization capacities of these mixed surfactant systems are higher than that of the individual surfactant system. From these results, these mixed surfactant systems can be employed in many environmental applications including enhanced contaminant extraction from subsurface water, and removing organic pollutants from wastewater.