OXIDATION OF FE(CN)6(4-) BY S2O8(2-) IN AOT OIL-WATER MICROEMULSIONS

The oxidation of hexacyanoferrate(II) by peroxodisulfate has been studied in sodium bis(2-ethylhexyl) sulfosuccinate (aerosol-OT or AOT)-oil-water microemulsions at 298.2 K. The rate of this reaction is appreciably higher in a microemulsion than when it takes place in a conventional aqueous solution. The dependence of the rate constants on the surfactant concentration, on the nature of the oil phase and on the molar ratio w = [H2O]/[AOT] has been investigated. Results show that when the AOT concentration remains constant, the reaction rate increases by decreasing the molar ratio, w. For a given [H2O]/[AOT] value, the reaction rate shows no dependence on the surfactant concentration or on the nature of the oil phase.