ABSTRACT
Microemulsions are macroscopically homogeneous mixtures of oil, water, and surfactant, which on the microscopic level consist of individual domains of oil and water separated by a monolayer of amphiphile. Pioneering work by Winsor P. A., Shinoda K., and others systematized the knowledge about phase behavior of oil-water-surfactant systems. The phase behavior of a three-component system can, at fixed temperature and pressure, best be represented by a phase diagram. Microemulsions, mainly based on nonionic surfactants, have an established position in industrial cleaning of hard surfaces. In bioorganic synthesis, W/O microemulsions can be employed as "minireactors" both for condensation and for hydrolysis reactions. The presence of an oil-water interface may induce orientation of reactants in microemulsion systems, which in turn may affect the regioselectivity of organic reactions. Microemulsions have reached the state where there is rather good understanding of the basic principles involved.
