WETTING OF STRATIFIED SOLIDS

We discuss theoretically the wetting properties of "antagonistic solid structures": (a) a layer of low polarisability deposited on a high energy surface (eg by grafting). (b) a layer of high polarisability (eg metallic) deposited on a low energy surface. The polarisability of the liquid is chosen to be intermediate between those of the two solid components, and the liquid is assumed to be non volatile. Case (a) leads to partial wetting, where a droplet is in equilibrium with a dry solid. Case (b) leads to what we have called (1) pseudopartial wetting, where the droplet has a finite contact angle, but generates a film of prescribed thickness e(m). This thickness will usually be comparable to the size of the solid surface layer (e-alpha). We describe both the statics and the dynamics of formation of these thick films.