Principles of emulsion formation

The phenomena occurring during emulsion formation are briefly reviewed. Droplet break-up in laminar and in turbulent flow is discussed and quantitative relations are given. The roles of the surfactant are considered, i.e. lowering the interfacial tension (and thereby facilitating break-up) and preventing recoalescence (via the Gibbs-Marangoni effect), in relation to the time scales of the various processes occurring.