Improved corrosion protective performance of hybrid silane coatings reinforced with nano ZnO on 316 L stainless steel

In this research, silane hybrid coatings based on γ-glycidoxypropyltrimethoxysilane/ methyltrimethoxysilane/ 3-aminopropyl trimethoxysilane (GPTMS/MTMS/ APS) were produce by sol-gel method. ZnO nanoparticles were embedded in the silane coating and this exclusive silane coating was employed to 316 L stainless steel (SS) substrates by the dip-coating method. The surface characteristics of the samples were examined by FTIR analysis, XRD, SEM-EDS, and contact angle measurements. Further, the corrosion protection behavior of the coatings was examined in 3.5 wt% aqueous NaCl solution using potentiodynamic polarization, EIS, and SECM analysis. AFM was applied to determine the surface morphologies of the samples after the polarization test. Our results exhibited that the coatings enhanced the anti-corrosion performance of SS substrates. It was also obtained that the combination of GPTMS/MTMS/APS provided better corrosion protection properties and acts as a strong physical barrier to the corrosive molecules. The presence of nano ZnO further improved the protective barrier of the coating.