Surface-induced phase separation of binary polymer blends on the chemically patterned substrate

The patterned substrate with alternating SiO₂ and octadecyltrichlorosilane (OTS) self-assembled monolayers (SAM) was used to induce phase separation of PS (polystyrene) and PVP (poly2-vinylpyridine) binary polymer blend films. The PS- and PVP- phase were situated on the OTS and SiO₂ domains, respectively. It revealed that even though the characteristic length scales (D) of phase separation were different from the periods of prepatterned substrates (λ), if the surface interaction between each component and substrate is strong enough, the lateral growth of phase separation domains is significantly constrained and the domains replicate the surface patterns.