Structure, Solubilizing Properties and Catalysis by Reversed Micelles

Abstract

The structure, solubilizing properties and catalytic use of reversed micelles are reviewed in the light of up-to-date results. The manner of formation of reversed micelles is discussed from a thermodynamic point of view. Their size depends strongly on the nature of the surfactant, the amount of water and the nature of the organic solvent. The solvation water of the polar head- groups is always present in a strongly bound state, while the water molecules in the internal core are more mobile. The utility of probe molecules is shown in studying the interface or the water core: the results obtained by fluorescence quenching, multinuclei NMR, EPR or IR techniques are considered. Polar molecules are preferentially dissolved in water while the less polar molecules locate themselves at the interface. The peculiar behaviour of the water core and that of the interface are illustrated by the large catalytic effect of reversed micelles.