DOI: 10.1140/epje/i2002-10119-8
Formation of adhesive contacts: Spreading versus dewetting
E. Verneuil, J. Clain, A. Buguin and F. Brochard-WyartLaboratoire Physico-Chimie Curie, UMR 168-Institut Curie, 11, rue Pierre et Marie Curie 75231 Paris Cedex 05, France brochard@curie.fr
(Received 22 December 2002 / Published online: 29 April 2003)
Abstract
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
