Chapter 18 - Metal oxide and heterocyclic compound mixed composites as corrosion inhibitor

Abstract

Corrosion is the deterioration of metals and its alloys by undergoing chemical reactions within the environments where these are exposed. It is a constant and continuous problem, often difficult to eliminate completely, but the prevention would be a more practical and achievable approach than complete elimination. Over the years, considerable efforts have been deployed to find suitable corrosion inhibitors of different inorganic and organic origin capable of working in various corrosive media. Inorganic metal oxides such as Al2O3, Fe3O4, MgO, NiO, SiO2, TiO2, ZnO, ZrO2, FeTiO3, etc. are efficient corrosion inhibiting additives and anticorrosive coating materials. On the other hand, the organic based heterocyclic compounds containing nitrogen (N), oxygen (O), or sulfur (S) like heteroatoms have also been established as potential corrosion inhibitor used in several corrosive environments. Moreover, the composite of inorganic metal oxides and heterocyclic compounds have been found to enhance the corrosion inhibition efficiency of the metals and its alloys subjected to various corrosive media. In this chapter, the corrosion inhibition efficiency of the composites of inorganic metal oxides and heterocyclic compounds as corrosion inhibitor as well as anticorrosive coating materials have been overviewed. The metal oxide and heterocyclic compound composites assist in formation of passive barrier film on the targeted metals or metallic materials to impede corrosive degradation of these substrates. The mechanisms of corrosion inhibition exhibited by the metal oxide and heterocyclic compounds composites have been comprehensively discussed. The further innovations in designing the metal oxide and heterocyclic compound composites have been proposed.