Plasma Polymerization of HMDSO with an Atmospheric Pressure Plasma Jet for Corrosion Protection of Aluminum and Low-Adhesion Surfaces

Thin functional films were deposited on aluminum with an atmospheric pressure plasma jet using hexamethyldisiloxane (HMDSO) as precursor. A high dynamic deposition rate on the order of 450 nm · m · min−1 was achieved. Composition and structure of the thin films show a strong dependence on the downstream location of the precursor injection. A 4 mm downstream shift of the precursor injection increases the carbon content in the thin film by a factor of 2.5, as indicated by XPS analysis and alters the degree of cross‐linking according to the FTIR spectra. The coating with the low carbon content (17 at.‐%) provides corrosion resistance for aluminum 2024 unclad exposed for 96 h to a neutral salt spray test. The coating with the high carbon content reduces the adhesion of an epoxy resin to the surface and may be used as a release coating. Thin films can be deposited at very high deposition rates with an atmospheric pressure plasma jet using hexamethyldisiloxane (HMDSO) as precursor. Different functionalities of the thin films are achieved by using different downstream positions of the precursor inlet. The potential use of these coatings for corrosion protection and low‐adhesion applications is demonstrated.