title: Formation and stability of paraffin oil-in-water nano-emulsions prepared by the emulsion inversion point method.
abstract: Paraffin oil-in-water nano-emulsions stabilized by Tween 80/Span 80 were prepared using the emulsion inversion point method at different emulsification temperatures. Nano-emulsions with droplet size below 200 nm were formed above a critical surfactant-to-oil ratio of 0.20 at 50 degrees C. The main destabilization mechanism of the systems was found to be Ostwald ripening. An interesting phenomenon was that the Ostwald ripening rate declined as the surfactant concentration rose. Furthermore, flocculation was also found to contribute to the instability of the nano-emulsions, especially for those with low surfactant concentrations. Study on the electrophoretic properties of emulsion droplets revealed a negative value of the zeta potential, which was strongly dependent on the pH of the systems.
authors.affiliation: Key Laboratory for Colloid and Interface Chemistry of Education Ministry, Shandong University, Jinan, Shandong 250100, People's Republic of China.
authors.forename: Weirong
authors.initials: W
authors.lastname: Liu
authors.forename: Dejun
authors.initials: D
authors.lastname: Sun
authors.forename: Caifu
authors.initials: C
authors.lastname: Li
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Xu