Corrosion inhibition of mild steel using chitosan / TiO2 nanocomposite coatings

Abstract

Coatings tailored to corrosion protection of metallic substrates are of utmost relevance to ensure reliability and long-term performance of coated parts as well as the product value of the coated materials. Presently, there is a strong emphasis on the development of advanced functional and smart coatings for corrosion protection in different technological applications. This work aimed to develop a novel coating based on Chitosan Titanium dioxide (CS/TiO2) nanocomposite to evaluate its corrosion inhibition effect on mild steel. Chitosan Titanium dioxide (CS/TiO2) nanocomposite films were coated on mild steel by sol–gel process, dip coating technique. Sol–gel protective coatings have shown excellent chemical stability, oxidation control and enhanced corrosion resistance for metal substrates. Further, the sol–gel method is an environment friendly technique of surface protection which has traditionally been used for increasing corrosion resistance of metals. For this project, Chitosan Titanium dioxide (CS/TiO2) nanocomposite membranes were prepared using Tetrabutyl Titanate (TBT) as precursor and acetyl acetone as chelating agent by solution casting process. The prepared nanocomposite membranes were coated on a polished metal surface, dried and annealed at 120 °C for two hours. Corrosion protection behavior of these coated mild steel substrates in 0.1 N HCl solutions was evaluated by potentiodynamic polarization studies (Tafel), linear polarization studies (LPR), electrochemical impedance spectroscopy studies (EIS).