Synthesis of Self-healing Nanocoatings for Corrosion Protection

The intrinsic reactivity of AA2024 alloys makes the application of a corrosion protection system necessary before making them into use. Nanostructured hybrid sol-gel based coatings were produced in this research to protect AA2024 alloy from corrosion. In order to have active protection based on self-healing of defects, cerium nitrate corrosion inhibitor was introduced into the coating system. Boehmite nanoparticles were introduced into the silica based hybrid coating, via sol-gel method from Aluminium Isopropoxide precursor, to act as nanoreservoirs for the storage and prolonged release of the corrosion inhibitor. The morphology of the deposited films was studied by SEM. The chemical composition and distribution of the elements was studied by EDS. The anticorrosion and self-healing properties of the coatings were evaluated by Electrochemical Impedance Spectroscopy (EIS) method. The results showed that the high corrosion resistance performance of such coatings is due to the presence of encapsulated cerium nitrate corrosion inhibitor that can be released controllably at the defects within the coating, resulting in cerium hydroxide precipitation which hinders the corrosion reactions at defective sites.

کلیدواژه ها:

sol-gel ، self-healing ، nanoreservoirs ، hybrid coating ، corrosion inhibitor