Some Fundamentals of the One-Step Formation of Double Emulsions

Abstract

The recently introduced one-step process to form double emulsions is analyzed using generalized phase diagrams of water, ethylene oxide adduct surfactants, and hydrocarbons. With the process used, we found three factors to be involved in the successful formation of double emulsions. Temporary ultra-low interfacial tension allowed drops of irregular shape to exist, a large part of the emulsion formed a bicontinuous microemulsion at intermediate times, and the interfacial tension was temporarily reduced extremely by significant amounts of all three compounds transferred over the interfaces in different directions depending on the stage of the process.

Keywords:

• Double emulsions
• emulsification
• emulsion
• emulsion inversion
• formulation
• microemulsions
• phase diagrams
• surface chemistry
• surfactants
• ultralow interfacial tension

Financial support for this study was obtained from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior–Capes and Fundacao de Amparo a Pesquisa do Estado de Minas Gerais–FAPEMIG.