High internal phase emulsions: Catastrophic phase inversion, stability, and triggered destabilization

Dunstan, Timothy S.; Fletcher, Paul D.I.; Mashinchi, Saeed

Abstract

We have investigated the formation, drop sizes, and stability of emulsions prepared by hand shaking in a closed vessel in which the emulsion is in contact with a single type of surface during its formation. The emulsions undergo catastrophic phase inversion from oil-in-water (o/w) to water-in-oil (w/o) as the oil volume fraction is increased. We find that the oil volume fraction required for catastrophic inversion exhibits a linear correlation with the oil-water-solid surface contact angle. W/o high internal phase emulsions (HIPEs) prepared in this way contain water drops of diameters in the range 10-100 μm; emulsion drop size depends on the surfactant concentration and method of preparation. W/o HIPEs with large water drops show water separation but w/o HIPEs with small water drops are stable with respect to water separation for more than 100 days. The destabilization of the w/o HIPEs can be triggered by either evaporation of the oil continuous phase or by contact the emulsion with a solid surface of the "wrong" wettability. © 2011 American Chemical Society.

Citation

Dunstan, T. S., Fletcher, P. D., & Mashinchi, S. (2012). High internal phase emulsions: Catastrophic phase inversion, stability, and triggered destabilization. Langmuir : the ACS journal of surfaces and colloids, 28(1), 339-349. https://doi.org/10.1021/la204104m

• Journal Article Type: Article
• Online Publication Date: Dec 19, 2011
• Publication Date: Jan 10, 2012
• Deposit Date: Apr 7, 2022
• Journal: Langmuir
• Print ISSN: 0743-7463
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 28
• Issue: 1
• Pages: 339-349
• DOI: https://doi.org/10.1021/la204104m
• Keywords: Contact angle; Emulsions; Lipids; Surfactants; Water
• Public URL: https://hull-repository.worktribe.com/output/3597464