Chapter 11: Nanocomposites as Steel Corrosion Inhibitors – The Journey So Far

This chapter is focused on the progress made so far in the application of nanocomposites as corrosion inhibitors. Vital components of industrial machinery and tools are made of expensive metallic materials such as mild steel, aluminium and copper. Routine application of these equipment exposes these metallic components to unfavourable conditions capable of making them susceptible to corrosion. To salvage this counterproductive menace, efforts have been put into the development of corrosion inhibitors for steel – the commonly applied metallic material in industries. Graphene, graphene oxide, clay, carbon nanotubes, polymers, metal oxide nanoparticles and silica are a few of the materials that have been used as corrosion inhibitors. In this chapter, the performance of nanocomposite coatings as corrosion inhibitors from 2010 to date is extensively discussed through the data obtained from potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) studies. Nanocomposite coatings on the surface of a steel specimen succeeded in reducing the corrosion current (I_corr) for the protected metal by acting as a barrier or as active inhibitors with very high inhibition efficiency. The composites mostly reduced the corrosion rate through strong adhesion to the substrate as a formidable barrier against corrosive media.