Formation of adhesive contacts: Spreading versus dewettingE. Verneuil, J. Clain, A. Buguin and F. Brochard-Wyart
Laboratoire Physico-Chimie Curie, UMR 168-Institut Curie, 11, rue Pierre et Marie Curie 75231 Paris Cedex 05, France email@example.com
(Received 22 December 2002 / Published online: 29 April 2003)
A soft bead (radius ) is pressed with a force F against a hydrophobic glass plate through a water drop ("wet" JKR set-up). We observe with a fast camera the growth of the contact zone bridging the rubber bead to the glass. Depending on the approach velocity V, two regimes are observed : i) at large V a liquid film is squeezed at the interface and dewets by nucleation and growth of a dry contact; ii) at low velocities, the bead remains nearly spherical. As it comes into contact, the rubber bead spreads on the glass with a characteristic time (in the range of one millisecond) , where is the liquid viscosity. The laws of spreading are interpreted by a balance of global mechanical and viscous forces.
68.08.Bc - Wetting.
68.15.+e - Liquid thin films.
68.35.Np - Adhesion.
81.40.Pq - Friction, lubrication, and wear.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2003