Micellization of Cetyltrimethylammonium Bromide (CTAB) in Mixed Solvents and in the Presence of Potassium Bromide

Critical micelle concentration (cmc) of cetyltrimethylammonium bromide (CTAB) has been determined conductometrically in binary mixtures of water +cosolvent at various temperatures and in the presence of potassium bromide (2.0-14x10-3M). Dioxane and acetonitrile were used as cosolvents added to water. Addition of organic solvents to water increased the cmc value of CTAB, but the presence of KBr lowered cmc. Thermodynamic parameters of micellization process ([image omitted], [image omitted], and [image omitted]) were evaluated for different compositions of solvents and KBr. The pseudo phase model was used for thermodynamic calculations.