Current phenomenological know-how and modeling of emulsion inversion

This paper encompasses classic trends as well as recent advances in the und erstanding of emulsion inversion phenomena. The generalized formulation iss ue is first discussed from hydrophilic-lipophilic balance to the most recen t concepts. The so-called standard inversion line on the formulation-compos ition map exhibits several branches, referred to as transitional and catast rophic inversions, that bound normal and abnormal emulsion regions. Dynamic inversion is also discussed with its hysteresis zones, where both types of emulsions may be attained, depending upon the system's previous history of the formulation-composition map. Recent findings are reported concerning t he effect of variables with practical relevance (i.e., stirring energy, vis cosity of phases, surfactant concentration, and partitioning) on the standa rd and dynamic inversion patterns. State-of-the-art emulsion inversion mode ling is briefly discussed.