Multifunction Nanostructured Coatings

The active corrosion protection of metallic substrates can be achieved by addition of corrosion inhibitors to protective coatings. However, direct mixing of an inhibitor with coating formulations can lead to important drawbacks decreasing barrier properties of the coating and diminishing activity of the inhibitor. Also, soluble inhibitors can cause phenomena like osmotic blistering or be leached out spontaneously to the environment, which limits long-term performance and is environmentally pernicious. To overcome this problem and have controlled release of inhibitor different strategies of inhibitors storage in nanocontainers have been developed in order to produce smart self-healing coatings.

In this work novel protective nanostructured coatings with self-healing ability are presented. This effect is obtained on the basis of nanocontainers that release entrapped corrosion inhibitors in response to local pH changes or presence of corrosive species. The development of new nanocontainers for organic and inorganic corrosion inhibitors achieved is described, especially the most promising from industrial point of view, based on Layered Double Hydroxides (LDH). The combination of different of these nanocontainers in the same coating system has proved to be effective to accomplish further functions as antifouling and sensing.