PYRENE LIFETIME BROADENING IN SDS MICELLES

The fluorescence decay of pyrene in SDS micelles has been investigated with the use of the maximum entropy method (MEM). Lifetime distributions, especially broad at low SDS concentrations, have been recovered. Simultaneous studies of the Ham effect and the water-induced fluorescence band of 4-(9-anthryl)-N,N-dimethylaniline (ADMA) suggest that the interaction between pyrene and water is responsible for the lifetime distribution broadening. At high SDS concentrations the lifetime distributions are probably due to increasing polydispersity of micelles. The results point to the need of revising the traditional kinetic models based on the mono-exponential decay of pyrene in micelles in the absence of quencher. © 1990.