Self-repairing coatings containing active nanoreservoirs

Nanocontainers with the ability to release encapsulated active materials in a controlled way can be employed to develop a new family of self-repairing multifunctional coatings, which possess not only passive functionality but also rapid feedback activity in response to changes in local environment. Several approaches to fabricate self-repairing coatings on plastic and metal substrates were surveyed. The release of the active materials occurs only when triggered, which prevents leakage of the active component out of the coating and increases coating durability. This Review also covers some principles and recent developments in the fabrication of nanocontainers with good compatibility with the coating components, the possibility to encapsulate and upkeep active material, and permeability properties of the shell controlled by external stimuli. Depending on the nature of the sensitive components introduced into the container shell, reversible and irreversible changes of the shell permeability can be induced by various stimuli. Different responses can be then observed varying from fine effects like tunable permeability to more drastic ones like total rupture of the container shell.