Cyclic voltammetry investigation of the mixed micelles of conventional surfactants with L64 and F127

Cyclic voltammetry investigation has been performed for the binary mixtures of tetradecyltrimethylammonium bromide (TTAB), hexadecyltri methylammonium bromide (HTAB), and polyoxyethylene(23)laurylether (Brij 35), with triblock polymers. Pluronic L64 and F127, by using 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) as an electroactive probe at 25 degrees C. A variation in the peak current versus the total concentration of surfactant allowed us to evaluate the critical micellar concentration (cmc) and related parameters from regular solution theory along with the diffusion coefficient of the electroactive species. A variation in the micellar mole fraction of the ionic component suggests that the mixed micelles are rich in triblock polymer component in the ionic surfactant rich region of the mixture and vice versa. The regular solution interaction parameter (beta) indicates the formation of mixed micelles due to synergistic interactions which have been found to be more intense in the combinations of F127 rather than that of L64. (c) 2005 Elsevier B.V. All rights reserved.