THE MOVING CONTACT LINE OF A DROPLET ON A SMOOTH SOLID

The slip velocity near the contact line of a liquid drop is considered to be generated by the shear stress induced by a nonuniform interaction potential in the liquid. Near the contact line, this interaction potential differs from that in a semi-infinite liquid and depends upon the distance x to the leading edge. Einstein's equation is used to relate the slip velocity to the force acting upon a molecule located on the solid surface. The equation derived for the slip velocity at the leading edge on the basis of these dynamical considerations coincides with that obtained previously by the author by considering that the force is generated by the gradient of the chemical potential. However, the slip velocity decays to zero as x(-4) in the latter case and as x(-3) in the former. (C) 1995 Academic Press, Inc.