Rheological studies of freely suspended soap films

We have developed an original viscometer that allows the determination of the viscoelastic properties of freely suspended soap films. We have found that soap films have a very high shear viscosity and a small shear modulus that might be associated with a glassy (gel-like) behavior. The incorporation of polymer chains inside the soap films does not change very significantly these viscoelastic properties that are governed by the dense packing of the surfactant in the interfacial films; nevertheless, the role of the polymer can be qualitatively described by scaling laws.