ABSTRACT
The phenomenon of spontaneous emulsification is reviewed with emphasis on results obtained in recent years. Several recent studies have provided insight into the mechanism of selfemulsification of oils brought into contact with water with gentle stirring to form oil-in-water emulsions consisting of small droplets. In particular, diffusion and/or chemical reactions can cause changes in composition or environment and hence in spontaneous curvature of surfactant films between oil and water, which in turn cause inversion from an oil-continuous to a watercontinuous microemulsion. Since the latter is not able to solubilize all of the oil present, local supersaturation and subsequent nucleation of oil droplets occurs. Under suitable conditions in some systems the lamellar liquid crystalline phase forms during the inversion process and coats the small droplets, thereby hindering coalescence and reducing the initial surfactant concentration required to obtain small droplets.
