Chapter 4 - Transitional Nanoemulsification Methods

Abstract

This chapter reviews low-energy transitional emulsification methods for fabricating nanoemulsions. These methods are based on phase transitions of nonionic surfactants (PEGylated surfactants) related to a sudden change in their relative solubility in the oily phase and aqueous phases. This irreversible process gives rise to kinetically stable dispersions of oil-in-water nanoemulsions. This chapter presents a comprehensive description of the phase behavior of nonionic surfactants and their impact on emulsification. The common link between nonionic surfactant phase behavior and the formation of nanoemulsions by both phase inversion temperature and spontaneous emulsification methods is then described. A clarification of the importance differences between nanoemulsions and microemulsions is given. The last section provides insights into the potential applications of transitional emulsification processes for fabricating nanoemulsions.