Since the fi rst scientifi c description in 1943, by Hoar and Schulman [1], on typically transparent oil-water chemical systems, innumerous academic and technological investigations on microemulsions have been reported and research activities in this area are continuously growing. The term “microemulsion” itself, however, was suggested by Schulman and coworkers only in 1959 [2], and has been used ever since to refer to dispersed, macroscopically homogeneous, thermodynamically stable, optically transparent, single-phase systems, formed by the spontaneous solubilization of two otherwise immiscible liquids, in the presence of surfactants. In some cases, short-chain alcohols or amines are added to the mixture as cosurfactants, which act by reducing interfacial tensions to very low levels, promoting distinct interactions at the interface and improving the fl uidity of the interfacial fi lm. The microemulsion can then be formed by the intimate dispersion of one liquid in the other, as droplets.