Microemulsions are thermodynamically stable dispersions of water-in-oil or oil-in water formed by the addition of either surfactants or mixtures of surfactant-cosurfactant. These systems are microscopically heterogeneous but macroscopically homogeneous The dispersed oil or water droplets can act as microreactors having properties different from bulk properties, so a chemical reaction undertaken in the microaqueous pool of the microemulsion is under a different environment from "bulk" condition.