title: Extension of a suspended soap film: a homogeneous dilatation followed by new film extraction.
abstract: Liquid foams are widely used in industry for their high effective viscosity, whose local origin is still unclear. This Letter presents new results on the extension of a suspended soap film, in a configuration mimicking the elementary deformation occurring during foam shearing. We evidence a surprising two-step evolution: the film first extends homogeneously, then its extension stops, and a new thicker film is extracted from the meniscus. The second step is independent of the nature of the surfactant solution, whereas the initial extension is only observed for surfactant solutions with negligible dilatational moduli. We predict this complex behavior using a model based on Frankel's theory and on interface rigidification induced by confinement.
authors.affiliation: Institut de Physique de Rennes, UMR 6251 CNRS/Université de Rennes 1, 35042 Rennes Cedex, France.
authors.forename: Jacopo
authors.initials: J
authors.lastname: Seiwert
authors.forename: Martin
authors.initials: M
authors.lastname: Monloubou
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dollet
authors.forename: Isabelle
authors.initials: I
authors.lastname: Cantat