| Abstract
| - Time-resolved fluorescence quenching of excited state pyrene by halothane was investigated in aqueoussolutions of poly(oxyethylene)−poly(oxypropylene)−poly(oxyethylene) triblock copolymers, P84, P104, andF38, at 25 °C. The occupancy number of halothane in the block copolymer micelles and the dispersive factorwere obtained from nonlinear least-squares fitting of the immobile quencher-probe and dispersive kineticmodels, respectively. It is shown that these parameters depend on the concentration of halothane in the systemand the hydrophobic/hydrophilic balance of the block copolymers. The application of dispersive kineticsappears to be a suitable technique to investigate the self-aggregation behavior of self-assembly systems.Exponential series lifetime-distribution analysis was also carried out and the results support the presence ofaggregates of triblock copolymers in these systems. The results of this study suggest that halothane moleculesdistribute primarily in the core of the micelles but, upon saturation of the core, begin to locate in the coronaof the block copolymer aggregates.
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