Influence of surfactant structure on adsolubilization behavior of mixed cationic-nonionic surfactant admicelles

Abstract

In this research, we investigated the adsorption of surfactant and adsolubilization of toluene and acetophenone, in a binary system of cationic surfactant, CTAB, and nonionic surfactants with different hydrocarbon chain lengths, Triton X-165 and Triton X-305. These two nonionic surfactants were used to form mixed-surfactant admicelles with CTAB on precipitated silica at various molar rations. The results showed that in single-surfactant systems CTAB adsorbed on precipitated silica is much higher than Triton X-165 and Triton X-305, respectively. The presence of nonionic surfactant in mixed-surfactant systems had significant effect on the amount of surfactant adsorbed as well as the CMC of the system. From the adsolubilization studies, the presence of nonionic surfactants had little effect on the adsolubilization of toluene in mixed-surfactant systems. In contrast, synergistic effect resulting from mixed cationic-nonionic surfactants was more pronounced in the adsolubilization of acetophenone, especially in the mixed system having Triton X-305, which has higher number of EO groups than Triton X-165