Effect of surfactant micelles on the redox reactions of cresyl violet

Reaction of hydrated electron with cresyl violet (CV) has been studied in d ifferent surfactant micelles using pulse radiolysis technique. This reactio n. leading to the formation of transient semi-reduced species, slows down a nd the decay of the transient is considerably arrested in the micellar medi um. Interactions of these surfactants have also been studied in both micell ar and pre-micellar regions following the changes in absorption and emissio n characteristics of cresyl violet. Among the various surfactants investiga ted, anionic surfactants, particularly sodium lauryl sulphate (SLS) and sod ium dodecyl benzene sulfonate (SDDBS), show marked effect on these properti es. At surfactant concentrations below and above the CMC. formation of dye- surfactant complex and micellization of CV are observed, respectively. The association constant, K-A, for the formation of the complex and the binding constant, K-B, for the micellization of the dye are determined using the m ethod of iteration. The environment in terms of dielectric constant experie nced by CV inside the surfactant micelles has been estimated. Results of ot her surfactants, namely, bis (2-ethylhexyl) sulfosuccinate Na salt (BSS), c etyl trimethyl ammonium bromide (CTAB) and Triton X-100 (TX-100) have also been presented.