Porous anodic oxide film with self-healing ability for corrosion protection of aluminum

Nanopores in aluminum oxide film served as vessels for corrosion inhibitor to add self-healing ability. Aluminum oxide films were immersed into a solution containing corrosion inhibitor to fill the nanopores. To monitor polarization resistance, the aluminum oxide film was coated with polymer, which was then scratched with a knife-edge. Uniform and large nanopores demonstrated a higher level of polarization resistance. The corrosion inhibitor was released in two steps: a large release due to dissolution was followed by a more sustained release due to corrosion inhibitor desorption. [Display omitted] •Pores in aluminum oxide film were used as vessels for corrosion inhibitor.•Corrosion inhibitor could be inserted into the pores of aluminum oxide film.•Film with large and uniform nanopores showed the highest resistance.•Healing film was detected on the surface of scratched substrates.•Release of corrosion inhibitor occurred in two steps: large and then sustained.