Caratterizzazione di emulsioni stabili ottenute tramite inversione di fase

Emulsions are metastable systems, whose properties depend on the microstructure of the dispersed phase, and are relevant for many industrial applications and for several products used even in daily life. To stabilize the emulsions, emulsifying agents, molecules with an amphiphilic character, are added in order to decrease the interfacial tension between the two phases. The classical emulsion preparation process consists in dissolving the surfactant in the continuous phase, in which it has to be soluble, and to add the dispersed phase under appropriate agitation. An alternative protocol, recently attracting growing interest, is based on the phase inversion, a process whereby water-in oil (W/O) emulsion inverts into an oil-in-water (O/W) and vice versa to produce fine and concentrated emulsions with low mechanical energy requirements ! even with very viscous oils. The inversion happens when the affinity of the surfactant(s) changes by either changing the temperature or changing the composition of the surfactant mixture at a constant temperature, or by subjecting emulsion to high deformation. In this work we describe a protocol for the formation of stable emulsions by phase inversion.