Self Healing Hybrid Coating for Aggressive Environment

C. Vashisth, R. Potrekar, N. Roy Choudhury, N.K. Dutta
University of South Australia, AU

Keywords: self healing, nanotube, protective coating, active ingredient


Self healing is a desirable property of a coating on metallic substrate to help arrest the development of micro-cracks and the propagation of corrosive species to the interfacial layer and eventually to the substrate. While many approaches to self healing have emerged recently based on liquid phase healing agent, phase separated healing agent, however, they have the limitation to supply the healing agents repeatedly at the damaged area. The use of hollow tube with controlled release active ingredient offers a novel approach to deliver sustainably the anticorrosive agents at the crack plane. With a view to achieve such self healing characteristics, nanotubes based on aluminosilicate have been employed as nanocontainers for active ingredients in a new generation of protective coating. The potential of active ionic liquid entrapped nanotube in coating layer has been explored in this work for corrosion protection of metal. Coatings have been prepared from organometallates and nanotube compositions and applied to clean steel substrates via dip coating. The nanotube based hybrid coating is found to be uniform, dense and essentially defect free. The release curve of the anticorrosion agent from the nanotube demonstrates the sustained release behavior efficient for corrosion protection and self healing characteristics.