Abstract: The interaction between the alkylbenzene sulfonate Gemini surfactant Ia and the conventional nonionic surfactant C10E6 was investigated. The critical micelle concentrations of different mixtures were measured by surface tension measurement in aqueous solution at different temperatures. The results suggested that the critical micelle concentration of different mixtures at any mole ratio was lower than that of either pure Ia or C10E6 surfactant, indicating synergetic behavior. The cmc values for pure Ia, C10E6 surfactant, and their different mixtures at any mole ratio increased with increasing temperature. And the interaction parameter β values for the mixed micelles were negative, showing attractive interaction between these surfactant molecules. The micelle aggregation number (N) was measured using a steady state fluorescence quenching method. The N values of the mixed surfactant system were larger than that of pure Ia but lower than pure C10E6 at all mole ratios. The micropolarity of micelles becomes small gradually with the increase of the mole ratio of the Gemini surfactant Ia.

Key words: Anionic Gemini surfactant, Nonionic surfactant, cmc, Micelle aggregation number, Micropolarity