Preparation and corrosion resistance of SiO₂ or TiO₂ nano particles/fluorinated polyacrylate polymer composite coatings

SiO₂ or TiO₂ nanoparticles/fluorinated polyacrylate polymer (PFHI) composite coatings with thickness of 1 μm were prepared by incorporating nanoparticles into PFHI solution followed by dip-coating and thermal curing. The effects of the amount of SiO₂ or TiO₂ nanoparticles on the surface properties and corrosion resistance of the composite coatings were investigated. The corrosion electrochemical property of the SiO₂ or TiO₂/PFHI composite coatings in 3.5wt% NaCl solution was investigated by Tafel curves and electrochemical impedance spectroscopy (EIS). XPS, attenuated total reflection Fourier transform infrared (ATR-FTIR), TG-DTA, SEM, optical contact angle (OCA) were used to characterize the composite coatings. The results show that the addition of SiO₂ or TiO₂ nanoparticles could greatly improve the corrosion resistance of the PFHI coatings. The SiO₂/PFHI composite coating with SiO₂ to PFHI of 0.3 in mass ratio exhibits the best electrochemical corrosion resistance performance and the penetration resistance R_ct is increased by two order of magnitude compared with the neat PFHI coating. The SiO₂ or TiO₂ nanoparticles combine with the PFHI tightly and increase the coating surface roughness to form the compact composite coatings, improving the hydrophobicity and compactness and the corrosion resistance of SiO₂ or TiO₂/PFHI composite coatings.