The @A00051@ of a @C01033@ in solution by the addition of a surfactant at a concentration higher than its @C01395@ so that the reaction can proceed in the environment of surfactant aggregates (@M03889-1@). (Rate enhancements may be due, for example, to higher concentration of the reactants in that environment, more favourable orientation and @S05747@ of the species, or enhanced rate constants in the micellar pseudophase of the surfactant aggregate.) @M03889-2@ formation can also lead to a decreased reaction rate.