Dynamics of moving contact lines
by
Jan Rosenzweig
Department of Applied Mathematics & Theoretical Physics, University of Cambridge, UK
Coauthors: O.E. Jensen (DAMTP, University of Cambridge)

This talk treats the notorious problem of the spreading of a thin film on a solid surface under the action of surface tension. The principal difficulty concerns the boundary conditions to be applied at the contact lines at the edges of the film. I shall derive the formal asymptotic expansion for this problem away from the contact line and allow the intrinsic stress singularity to be relieved by any of a number of physical mechanisms, including evaporation/condensation, van der Waals forces, electrostatic potentials and some others. In all these cases, formal matching up to logarithmic orders results in a generic set of leading-order boundary conditions to be applied at the contact line, which depends only on two material parameters. The contact line condition involving the dynamic contact angle is similar to Tanner's Law, but has a different limit for small capillary number. This difference may account for why Tanner's Law is a poor approximation to some published experimental data. The results will be applied to derive the time dependence of surface-tension-driven spreading of droplets on solid surfaces.

Date received: March 8, 2000

Copyright © 2000 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cadz-41.