DYNAMICS OF SPREADING OF A LIQUID-DROP ACROSS A SURFACE CHEMICAL DISCONTINUITY

We report an experimental study of the dynamics of a liquid ridge straddling a chemical discontinuity which separates two different solid surfaces. Measuring the displacements and contact angles on both sides, we describe in detail the different regimes of motion and in particular a stationary regime which corresponds to uniform translation. These results are in qualitative agreement with a theoretical model, although we see a deformation of the drop shape when compared to a circular profile, which is the currently admitted hypothesis.