FLUORESCENCE QUENCHING IN MICELLES IN THE PRESENCE OF A PROBE-QUENCHER GROUND-STATE CHARGE-TRANSFER COMPLEX

Time-resolved fluorescence-quenching experiments combined with stationary measurements are used to investigate nonfluorescent ground-state charge-transfer-complex formation of pyrene with methylviologen in sodium dodecyl sulfate (SDS) micelles. The fluorescence-quenching decay surface and the experimental data from stationary measurements were interpreted by a model based on the statistical aspects of probe-quencher association in a micellar confinement. Data analysis allowed the determination of all model parameters related to the dynamic and static quenching process. In the region of 0.035-0.156 M surfactant concentration, the average aggregation number of the SDS micelles changed from 60 +/- 3 to 81 +/- 3, the value of the intramicellar quenching rate constant was in the range (5.33-4.22) X 10(7) s-1, and the ''apparent'' complexation constant was nearly constant at 293 K.