Novel and self-healing anticorrosion coatings using rare earth compounds

Self-healing materials have the ability to repair themselves and recover functionality after degradation, damage and failure. This chapter reviews recent developments in self-healing protective coatings which contain rare earth-based inhibiting compounds for active corrosion protection of metals. These new 'green' inhibitors are being developed as substitutes for chromate-based inhibitors. Different types of organic, hybrid and metallic systems are considered, with particular emphasis on thin sol-gel based layers. The main strategies for encapsulation of RE inhibitors are also reviewed. Significant future effort is required to improve the properties of organic coatings and to explore new self-healing coating alternatives that allow controlled release of the inhibitor.