Micellization, aggregation, interaction, and solubilization behaviors of mixed solutions of cationic gemini and nonionic surfactants

The micellization properties of mixed aqueous solutions of a cationic gemini surfactant (CGS) and Triton X-100, a conventional non-ionic surfactant, with various mole fractions, were determined by measuring the surface tension at different temperatures. Various theoretical models were used to analyze the behavior of this mixed system. The interactions between CGS and Triton X-100 were determined to be non-ideal and synergistic. The calculated interaction parameters (β^M) have negative values at all temperatures and for all mole fractions, showing attractive interactions. It was found that increasing the mole fraction of Triton X-100 significantly increased the synergistic effect (more negative values). Micellar aggregation number (N_agg) values of pure surfactants and their mixtures in different ratios were obtained with the steady-state fluorescence quenching method. Furthermore, the molar solubilization ratio of Sudan III organic dye in all surfactants aqueous systems was obtained using UV–Visible spectrophotometry. At concentrations above critical micelle concentration, the solubility of Sudan III in water was substantially increased linearly for all systems and it was observed that the enhancement was even more significant for mixed surfactant systems.