Properties of emulsion mixtures

Abstract

Emulsions are systems which exhibit some memory of their manufacturing process; thus, the same surfactant-oil-water system can result in different emulsions. This paper deals with the mixing of emulsions with the same formulation, but different drop-size distributions.The two base emulsions are prepared in different vessels according to a standard procedure to attain fine or coarsely dispersed systems, with wider or narrower size distribution. Then, they are poured together and blended with a gentle stirring.Experimental evidence indicates that the characteristics of the dropsize distribution of the emulsion mixture has a strong influence on the properties of the emulsion mixture, such as its viscosity and its stability. A considerable viscosity reduction can be attained by mixing two emulsions with identical formulation but different size distributions. The features which are found to promote the viscosity reduction are a strong bimodality of the combined distribution, a deep gap between modes, and a certain degree of polydispersity.