Phase inversion of particle-stabilised perfume oil-water emulsions: experiment and theory

Binks, Bernard P.; Fletcher, Paul D. I.; Holt, Benjamin L.; Beaussoubre, Pascal; Wong, Kenneth

Abstract

Phase inversion of fumed silica particle-stabilised emulsions of water and perfume oil can be effected in three ways. The transitional inversion from water-in-oil (w/o) to oil-in-water (o/w) occurs upon increasing the particle hydrophilicity for 9 oils of different polarity and structure. Results are compared for systems in which particles are pre-dispersed in one of the bulk phases and for those in which a novel powdered particle method is used. Using a simple theory involving the surface energies of the various interfaces, the contact angle theta of a particle with the oil-water interface is calculated as a function of the particle hydrophilicity. Assuming phase inversion occurs at theta - 90 degrees, very good agreement is obtained for all oils between the calculated and experimental particle hydrophilicity required for inversion in the case of the powdered particle method. Inversion from o/w to w/o induced by simply increasing the particle concentration is shown to be as a result of changes in the aggregation state of the particles influencing their wettability. Finally, catastrophic phase inversion from w/o to o/w is achieved by increasing the volume fraction of water, and multiple emulsions form around inversion in a system containing only one particle type. Results of the latter two inversion routes are combined to develop an emulsion compositional map allowing a variety of emulsions with different characteristics to be described by varying the relative amounts of the three components.

Citation

Binks, B. P., Fletcher, P. D. I., Holt, B. L., Beaussoubre, P., & Wong, K. (2010). Phase inversion of particle-stabilised perfume oil-water emulsions: experiment and theory. Physical chemistry chemical physics : PCCP, 12(38), 11954-11966. https://doi.org/10.1039/c0cp00558d

• Journal Article Type: Article
• Acceptance Date: Jun 24, 2010
• Online Publication Date: Aug 23, 2010
• Publication Date: Oct 14, 2010
• Journal: PHYSICAL CHEMISTRY CHEMICAL PHYSICS
• Print ISSN: 1463-9076
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 38
• Pages: 11954-11966
• DOI: https://doi.org/10.1039/c0cp00558d
• Keywords: Colloidal particles; Interfacial-tension
• Public URL: https://hull-repository.worktribe.com/output/396263