New Challenges for Emulsions: Biosensors, Nano-reactors, and Templates

Abstract

Emulsions have a widespread range of applications; the most important ones so far include cosmetics, food, detergents, adhesives, coatings, paints, surface treatments, road surfacing, and pharmaceuticals. Scientific information about emulsions can certainly direct their use in potentially new fields that are linked to new markets or can simply provide new tools for basic research. Nano- or microtechnologies are rapidly expanding today and in many cases they markedly overlap with colloidal science. Indeed, colloids have typical length scales that are intermediate between molecules and macroscopic objects; they can thus act either as minute substrates or as reservoirs. They can also be manipulated by applying external forces to selectively sort desirable products, or to create local stress-controlled conditions. Liquid droplets can compartmentalize minute amounts of defined reactants, either to screen a large compound library or parallelize a directed process imposed by confinement. We present in this chapter some particularly promising examples of new applications of emulsions in nano- or microtechnologies, related to biotechnologies, biophysics, and processing of high-tech materials for micro-optics.