The clouding phenomena of mixed surfactant (non-ionic Triton X-114 + cationic gemini 16-5-16) solutions: Influence of inorganic and organic additives on the cloud point

Abstract

In this investigation, we have studied the micellization of non-ionic surfactant, Triton X-114 (by surface tension measurement) and cationic gemini surfactant, pentanediyl-1,5-bis(dimethylcetylammonium bromide) (16-5-16) by surface tension, conductivity and dye solubilization methods and the clouding phenomena of mixed surfactant (non-ionic Triton X-114+cationic gemini 16-5-16) system in aqueous solution. The critical micelle concentration (CMC) of Triton X-114 and 16-5-16 were measured and their surface properties and thermodynamics were evaluated. In aqueous solution, non-ionic surfactant, Triton X-114 undergoes phase separation or cloud point (CP). Herein, we also report the influence of additives (e.g., electrolytes, sugars, amino acids, etc.) on the CP of Triton X-114 in aqueous solutions. The CP showed a concentration dependent variation in the absence of any added compound (additives). With the addition of additives, the CP values were found to decrease and increase. It is found that the CP of pure Triton X-114 is concentration dependent; and the presence of gemini surfactant (16-5-16) increases the CP. However, all additives in the presence of the gemini surfactant (i.e., Triton X-114+16-5-16 system) decrease the CP. The results are discussed by taking into consideration the nature of the additives. The thermodynamic parameters are also evaluated at CP.