Preparation and Corrosion Protective Properties of Oxide Nanoparticle Coatings Doped with Organic Inhibitor

Metallic substrates are pre-treated before application of an organic paint in order to improve adhesion between the polymer and the metal and to provide additional long term corrosion protection. SiO2, ZrO2, Al2O3, TiO2 and CeO2, etc. all have very good chemical stability and can provide effective protection to metal substrate.TiO2 has excellent chemical stability, heat resistance and low electron conductivity, making it an excellent anti-corrosion material. Oxide nanoparticle coatings have been synthesized from Tetra-n- butylorthotitanate precursor by sol-gel method. Benzotriazol, as corrosion inhibitor, was added into the oxide nanoparticles. The chemical composition and the structure of the sol-gel coatings were studied by XRD (X-ray diffraction), EDS (energy dispersive x-ray spectroscopy) and AFM (atomic force microscopy), SEM (scanning electron microscopy) respectively. The evolution of the corrosion protection properties of the sol-gel coatings was studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results show that doping the sol-gel coating with benzotriazol leads to improvement of the corrosion protection. The Titanium oxide nanoparticles present in the sol-gel coating seem to act as reservoirs for adsorption of inhibitor and release them during contacts with corrosive components.

کلیدواژه ها:

Nanoparticle ، Sol-gel coating ، Organic inhibitor ، EIS