Dense and Anti-Corrosion Thin Films Prepared by Plasma Polymerization of Hexamethyldisilazane for Applications in Metallic Implants

Abstract Plasma polymerized hexamethyldisilazane (ppHMDSZ) thin films with specific thickness and density coated on substrates (ppHMDSZ/substrate) to promote the corrosion resistance for the potential applications in metallic implants is reported in this study. Comparing with the conventional anti-corrosion thin film coatings, plasma polymerization method provided an effective, dry, and simpler process, which allowed to prepare dense thin films with the thickness of a few hundred nanometers. This study proposed that the anti-corrosion behavior could be correlated closely to the density of thin film coated on stainless steel (SS) that can be precisely controlled by the plasma deposition time. The physico-chemical properties of the as-prepared ppHMDSZ thin films were evaluated by field-emission scanning electron microscope (FE-SEM), water contact angle (WCA), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and electron spectroscopy for chemical analysis (ESCA). The corrosion resistance of the ppHMDSZ coated stainless steel (ppHMDSZ/SS) was improved by depositing ~140 nm in thickness and 1.15 g/cm3 in density which reduced 90 % of the original corrosion performance against the corrosion in Hank’s solution, measured by potentiodynamic polarization tests. The resultant ppHMDSZ thin film coatings allowed to protect substrates toward corrosion and can be further applied in implants for tissue engineering and biomaterials.