College de France

Abstract:

We describe situations of extreme hydrophobicity, where drops are found to look like pearls when deposited on a solid. First, we are interested in the statics: how to design solids exhibiting such a property? Then, we look at different dynamic situations: sliding (or rolling) of a drop along a tilted plane, impact (possibly associated with bouncing) of a drop on such a solid. In each case, original behaviors are found, which are not simple extrapolations of what can be observed at smaller contact angles.