An environmental friendly self-healing coating with Silane/Ce-ZSM-5 zeolite structure for corrosion protection of aluminum alloy

This paper investigated the preparation of new environmental, pH stimulation response nanocontainer enhanced, self-healing, and efficient anti-corrosion coating for aluminum alloy protection. Silane/Ce-ZSM-5 coating with improved morphology was successfully synthesized on aluminum alloy surface, through the new proposed “hydrothermal crystallization - ion exchange - self-assembled seed growth - hot pressing” technology, in which ZSM-5 molecular sieve was served as pH stimulation response nanocontainer. The corrosion resistance and self-healing ability of the coating in 3.5 wt% NaCl solution were further investigated by the combined analysis of SEM, EIS, LEIS, ICP-MS characterization and 3D microscopic observation. The experimental results showed that the prepared silane-Ce-ZSM-5 coatings exhibited excellent corrosion protection and self-healing ability, which was attributed to the pH stimulation release of corrosion inhibitor Ce3+ when the coatings were damaged. The ZSM-5 zeolites generated Ce(OH)3 or CeO2 precipitates to gradually fill the aluminum alloy defects, thus forming a dense protective layer and inhibiting the corrosion activity.