Lobo and Wasan (1989) examined the stability of soybean oil/water emulsions, stabilized by a protein and a nonionic emulsifier, along with the interfacial rheological properties and dynamic thin film behavior. The protein was found to cause a large increase in the interfacial viscosity that inhibits film drainage and, hence, stabilizes the emulsions. On the other hand, emulsions containing the nonionic emulsifier, which does not affect the interfacial viscosity appreciably, were also found to be stable. Draining thin films formed from such a nonionic micellar solution was found to exhibit sharp thickness transitions, which is indicative of the stratification phenomenon. With such observations, they proposed a mechanism of emulsion stability, that is, due to the presence of long-range structural forces in thin films over the distance of the order of 1000 Å and the formation of colloid crystal-like structures within the film.