Nanoemulsions: the properties, methods of preparation and promising applications

The properties of nanoemulsions and various methods for their preparation including the high-energy and low-energy emulsification methods and the combined methods are reviewed. Among the high-energy methods, the emphasis is placed on high-energy stirring, ultrasonic emulsification, high-pressure homogenization including microfluidics and membrane emulsification. Among the low-energy emulsification methods, the attention is focused on the phase inversion temperature method, the emulsion inversion point method and the spontaneous emulsification. Using a combined method, which includes the high-energy and low-energy emulsification, it is possible to prepare reverse nanoemulsions in highly viscous systems. Main advantages and limitations of different methods of nanoemulsion preparation are discussed and the potential fields of nanoemulsion applications are considered. The bibliography includes 255 references.