Effects of Various Alcohols and Salts on the Mixed Micellization of Cationic Surfactant (CPC) with Nonionic Surfactant (TX-100)

The values of critical micelle concentration for the mixed micellization of cetylpyridinium chloride (CPC) with polyoxyethylene (10) p-isooctylphenyl ether (TX-100) were measured as a function of overall mole fraction of CPC (alpha(1)) at 298.15 K by using the UV-Vis spectrophotometric method. Various thermodynamic parameters were calculated and analyzed by the equations derived from the non-ideal mixed micellar model. The results show that there is a strong interaction between two surfactants in a micellar state so that a great negative deviation has been occurred for the micellization of CPC/TX-100 mixed system. A straight long alcohol makes greater effects than a branched short alcohol. Alcohols are affecting only the activity of nonionic surfactant in a micellar state, but salts are affecting both the activities of cationic surfactant (CPC) and nonionic surfactant (TX-100). We can also know that strong inorganic salts are more effective than weak organic salts on the micellization of the CPC/TX-100 mixed system.