Advances in fabrication of emulsions with enhanced functionality using structural design principles

Emulsion science and technology has been used for many years to create a diverse range of commercial products, including pharmaceuticals, foods, agrochemicals, lubricants, personal care products, and cosmetics. The majority of these products are conventional emulsions consisting of droplets of one liquid dispersed in another immiscible liquid, e.g., oil-in-water emulsions. Recently, there has been growing interest in extending the functional performance of emulsion-based products using structural design principles. This article reviews recent developments in the creation of structured emulsions, including multiple emulsions, multilayer emulsions, colloidosomes, microclusters, filled hydrogel microspheres, and hybrid systems. The structure, fabrication, properties, and potential applications of each type of structured emulsion are discussed. In addition, recent advances in the fabrication of emulsion droplets with specific properties (size, charge, interfacial properties, and physical state) are also reviewed, since these are the basic building blocks of structured emulsions.