Thick and very stable aqueous films between oil phases are obtained in systems where surfactant diffuses across the interfaces, towards the film. An osmotic pressure difference exists between the film interior and the surrounding aqueous meniscus. This is due to surfactant aggregates (micelles); it pushes the film surfaces apart, giving rise to intensive liquid circulation and exchange of mass with the meniscus.

• Received 21 November 1994

DOI:https://doi.org/10.1103/PhysRevLett.75.264