Surfactant-Concentration Effects in Photoinduced Electron Transfer from Pyrene to Cupric Ions in Sodium Dodecyl Sulfate Micelle Solutions

Article abstract of DOI:10.1021/j150660a014

The decay of pyrene fluorescence and the quantum yield of pyrene cations were measured by using the laser photolysis method in sodium dodecyl sulfate (SDS) micelle solutions containing both pyrene and cupric dodecyl sulfate at 40 deg C.The decay curve of the pyrene fluorescence deviates from the first-order rate law at SDS concentrations below 0.2 M, as alredy known, but becomes first order at higher SDS concentrations.The rate shows incontinuity between 0.2 and 0.5 M SDS.The cation quantum yield remarkably increases with the SDS concentration: For 10 mM of cupric ion, the quantum yields were 0.25 and 0.60 at SDS concentrations of 0.05 and 0.8 M, respectively.These results can be explained in terms of involvement of large rodlike micelles in which the portion of the net electron transfer in quenching is larger than in usual spherical micelles.