A Study of the Authophobic Dewetting in Thin Polymer Films

摘要

We have investigated the dewetting behaviour of a thin polystyrene film on top of cross-linked network of the same polymer. By changing the cross-linking density, the dynamic of the dewetting is modified. The behaviour of the contact angle and dewetting velocity can be related to the interfacial width between the polymers. We observe moreover that while the lost of entropy of the network connected to the penetration of the free chains will favour the dewetting; the possible presence of ‘‘connectors’’ between the layers will tend to stabilize the wetting. By modifying the entropy of the mesh by swelling the cross-linked system with a reservoir of the same polymer, the mesh is saturated and a stable interface without interdiffusion between the layers is obtained: in this case a constant contact angle and slippage length are obtained. Networks with higher cross-linking density are more difficult in general to swell - the mesh size is smaller - and the complete saturation is not reached.