Chapter 3 - Multifunctional and smart organic–inorganic hybrid sol–gel coatings for corrosion protection applications

Abstract

The degradation of materials by corrosion action involves high financial expenses in its prevention and in its recovery. Therefore the development of multifunctional and smart organic–inorganic hybrid (OIH) coatings for corrosion protection of metallic substrates is of tremendous importance. These coatings ensure long-term performance of coated substrates and, therefore, their usefulness. This chapter reviews and highlights the most recent applications of multifunctional and smart OIH sol–gel coatings for corrosion protection. Multifunctional and smart coatings combine several functionalities for increased corrosion protection due to the ability to respond according to the exposed environment. Generally, the coating’s ability to respond requires an external trigger. These triggers may include, for instance, chloride ions, the presence of moisture, pH fluctuations, redox activity, mechanical stress, and temperature. These functionalities can be simply achieved by encapsulating different agents within the OIH matrices, such as superhydrophobic additives, corrosion inhibitors, and antifouling agents. Additionally, this chapter focuses on the basic fundamentals of corrosion and sol–gel method and emphasizes the most recent trends in the field of multifunctional and smart coatings for corrosion protection of metallic materials in different environments. In conclusion the current and future needs for multifunctional and smart OIH coatings are debated.