A new mechanism of spontaneous emulsification: Relation to surfactant properties
Laboratoire de Physique Statistique de l'ENS,
24 rue Lhomond, 75 231 Paris Cedex 05, France
URA 1306 du CNRS, associé aux Universités Paris VI et VII
Accepted: 29 September 1997
A new mechanism of spontaneous emulsification is described and related to the surfactant phase behaviour and to the molecular architecture. Aqueous solutions of the anionic surfactant AOT are shown to form vesicular phases, due to the fact that the head and tail group of AOT are nearly balanced. When these phases are brought gently into contact with an oil by means of a micropipette, a flow of the surfactant aggregates towards the oil phase is observed. The incorporation of the oil into the surfactant bilayers leads to the formation of oil films within the bilayers that are unstable. The vesicles are consequently destabilized and "explode”, thereby dispersing the oil in the aqueous phase.
PACS: 82.70.Kj – Emulsions and suspensions / 68.10.-m – Fluid surfaces and fluid-fluid interfaces / 83.70.Hq – Heterogeneous liquids: suspensions, dispersions, emulsions, pastes, slurries, foams, block copolymers, etc.
© EDP Sciences, 1997