Proper Determination of Phase Diagrams while Nanoprecipitating Oils

The Ouzo effect is a generic process to generate colloidal dispersions from a variety of solutes. Whereas phase diagrams have been quite easily established when nanoprecipitating polymers, the case of oils is less straightforward. Indeed, the short-term stability of generated nanodroplets in water/solvent mixtures complexifies the identification of the diagram boundaries. This article proposes two complementary methods, namely, fluorescence microscopy and dynamic light scattering, to determine with fair accuracy Ouzo limits in ternary systems oil/solvent/nonsolvent, without and with a surfactant, respectively. This accuracy in PD determination opens the way to a better understanding and control of the aggregation events during the nanoprecipitation process.