Micellar Rate Effects: What We Know and What We Think We Know. (Reannouncementwith New Availability Information)

摘要

Chemical reactivity in micelles and similar association colloids (microemulsionsand vesicles) is generally treated in terms of pseudophase models with micelles and water regarded as distinct reaction regions. Overall rate (and equilibrium) constants depend upon reactant concentrations in each pseudophase and the appropriate rate (or equilibrium) constants. Quantitative treatments fit observed variations of overall rate constants with concentrations of surfactant, reactant, and for ionic reactions, of added electrolyte. Reactive and inert counter-ions compete and the competition is described by a pseudophase ion-exchange (PIE) model, or by solution of the Poisson-Boltzmann equation (PBE) with allowance for specific ion-micelle interactions. These treatments, and those based on direct estimation of reactant concentrations at micellar surfaces, show that second order rate constants are, with few exceptions, similar at micellar surfaces and in water.