Nanotextures fabricated by microwave plasma CVD: application to ultra water-repellent surface

Nanotextured surfaces of polymer sheets with high water-repellency were fabricated through a nano-replica process. First, ultra water-repellent silica thin films were deposited onto Si substrates by microwave plasma-enhanced CVD (MPECVD) using an organosilicon compound as a raw material. The nanotextures of the film surface were controlled by changing deposition pressure. Second, the surface nanotextures of the films were replicated to Ni molds by electroforming. Third, polystyrene (PS) was coated on the Ni molds by spin coating and the nanotextured PS replicas were fabricated by this process. The contact angles of the nanotextured PS replicas were 130°, while 90° were obtained for PS flat sheets.