A facile construction strategy of SiO2-modified anodic film on 304 stainless steel by introducing TEOS into fluoride-based ethylene glycol electrolyte

Abstract

Silane coupling agents have been widely used in various metal-based functional and structural applications, including super-hydrophobic self-cleaning materials and fiber-metal laminates. Therefore, the responsiveness of the metal matrix for silane coupling agents is critical to enhance the excellent performance brought by silane coupling agents. Here, the SiO2-modified anodization film was successfully fabricated on 304 stainless steel substrates, the most widely used metal materials, by introducing TEOS into fluoride-based ethylene glycol electrolyte. By introducing silicon-related functional groups on the anodization film, the responsiveness of the metal surface to silane coupling agents can be significantly improved, thus the surface hydrophobicity of SS substrate anodized in TEOS-electrolyte was improved more obviously than that in raw-electrolyte. The sample prepared in TEOS electrolyte under 60 V for 3 h obtained a suitable morphology and the SiO2 micron particles were uniformly embedded in the film. Importantly, by comparing the composition and conductivity of the remained raw- and TEOS-electrolytes, the formation mechanism of the SiO2-modified film is plausibly proposed. The present work may offer a new path for the SiO2-modified anodization surface modification method of type 304 stainless steel substrate.