A Concise Review on Nano-emulsion Formation by the Phase Inversion Composition (PIC) Method

Nano-emulsion formation by the phase inversion composition method is reviewed. The relationship between phase behavior and nano-emulsion formation is revised with emphasis on the key role of phase transitions involving changes in the sign of the curvature of the surfactant layer (inversion) via zero-average-curvature structures such as bicontinuous microemulsions or lamellar liquid crystalline phases. The different low-energy methods that can be involved in a nano-emulsification process at constant temperature are also discussed.