A review on the Organic-Inorganic Compounds Including Corrosion Inhibitors; Investigating the Methods of Synthesis and the Mechanisms of Protection

One of the most common approache for protection of metals against corrosion is application of organic coatings. These coatings provide physical barrier against diffusion of water and ions to the metal surface. However, environmental issues such as UV irradiation, thermal and mechanical stresses (scratch and crack) are responsible for the coating damage, resulting in the creation of pores and defects in the coating matrix. Therefore, active corrosion inhibition and barrier protection action are required for metal protection against corrosion. One method for achieving an active corrosion inhibition effect is the use of inhibitive anti-corrosive pigments. Chromate is one of the most popular inhibitive pigments. Howevre, its use in organic coatings has been strongly restricted due to its toxic and carcinogenic nature. The organic/inorganic pigments can be categorized into barrier, sacrificial and active inhibitive pigments. Direct loading of corrosion inhibitors into the coating results in undesirable and negative effects on its curing and structural properties. One effective strategy for overcoming this issue is encapsulation of corrosion inhibitors into the micro-nano containers. In this study different methods for encapsulation of corrosion inhibitors and their inhibitive mechanisms are reviewed and discussed.