https://doi.org/10.1140/epjb/e2004-00037-9
Dissipation in the dynamics of a moving contact line: effect of the substrate disorder
Laboratoire de Physique Statistique de l'École Nomale
Supérieure, associé au CNRS et aux Universités Paris 6 et Paris 7,
24 rue Lhomond, 75231 Paris Cedex 05, France
Corresponding author: a rolley@physique.ens.fr
Received:
13
June
2003
Revised:
6
October
2003
Published online:
19
February
2004
We have studied the dynamics of the contact line of a
viscous liquid on a solid substrate with macroscopic random
defects. We have first characterized the friction force f0 at
microscopic scale for a substrate without defects; f0 is found
to be a strongly nonlinear function of the velocity U of the
contact line. In presence of macroscopic defects, we find that the
applied force F(U) is simply shifted with respect to by
a constant: we do not observe any critical behavior at
the depinning transition. The only observable effect of the
substrate disorder is to increase the hysteresis. We have also
performed realistic numerical simulation of the motion of the
contact line. Using the same values of the parameters as in the
experiment, we find that the experimental data is qualitatively
well reproduced. In light of experimental and numerical results,
we discuss the possibility of measuring a true critical behavior.
PACS: 46.65.+g – Random phenomena and media / 64.60.Ht – Dynamic critical phenomena / 68.08.Bc – Wetting
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004