Velocity Dependent Adherence: An Analytical Approach for the JKR and DMT models
Résumé
Recent Surface Forces Apparatus experiments on organic monolayers deposited on mica surfaces (Ruth M. and Granick S., Langmuir 14, 1804 (1998)) have evidenced an increase of the pull-off force with driving velocity, which has been interpreted as due to local viscoelastic dissipation at the contact edge. Following Maugis and Barquins, this phenomenon is modelled through a combination of the Johnson-Kendall-Roberts equations for the adhesive contact of elastic bodies and the Gent-Schultz approach to viscoelastic crack dissipation. We provide an approximate analytical solution for the pull-off force as a function of the driving velocity which is supported by the result of direct numerical integrations of the equations in a large range of velocities. We discuss the application of this model to the adherence of two mica surfaces supporting surfactant monolayers.