8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P6.34Fri 911:10-14:00Time evolution of foams made from emulsionsAnniina Salonen, 1 Romain Lhermerout, 2 Yumiko Yoshitake, 2 Fabrice Iannacone, 2Livia Gabou, 2 Aouatef Testouri, 2 Emmanuelle Rio, 2 Wiebke Drenckhan, 2 ArnaudSaint-Jalmes, 3 and Dominique Langevin 21 Laboratoire de Physique des Solides, Université Paris Sud, 91400, Orsay, France2 Laboratoire de Physique des Solides, Orsay, France3 Institut de Physique de Rennes, Orsay, FranceMixtures of foams and emulsions are found in many industrial products, where either they arepurposefully created for reasons of function and texture or they are an unwanted side productdue to the foaming of an emulsion during preparation or use. Interestingly, depending on thevolume fractions of the components, type of surfactant and oil used emulsions can stronglyincrease the stability of foams or can act as anti-foams. Although some research has beenconducted on emulsions as anti-foams [1], their use as stabilizing agents for foaming has so farbeen much less explored [2]. In either case both the foam and the emulsion evolve with time,the bubble (drop) size increases and the fluids eventually phase separate. In mixtures the agingof the emulsion will have an effect on the aging of the foam and vice versa. We have studied amodel foam-emulsion system using a single surfactant to stabilize both phases, thus changingfrom very unstable to long-lived foams. The time evolution of the systems has been followedusing light scattering techniques, with particular emphasis on the highly stable foams. In suchstable foams the emulsion droplets can get jammed inside the porous structure of the foam, thusmaking them interesting systems with which to study the effects of confinement on complex fluids.[1] N. D. Denkov, Langmuir 2004, 20, 9463.[2] K. Koczo, L. A. Lobo, D. T. Wasan, Journal of Colloid and Interface Science 1992, 150, 492.34