Application of Environmentally-Friendly Coatings Toward Inhibiting the Microbially Influenced Corrosion (MIC) of Steel: A Review

Abstract

Microbially influenced corrosion (MIC) is an electrochemical type of corrosion that is initiated, facilitated, or accelerated by bacteria and biofilms on the metal substrate. To inhibit MIC, coating methods have been widely used because of their effectiveness, ease of application, and low cost. Coatings used for MIC inhibition should have antibacterial and anticorrosive properties. Conventional coatings for MIC inhibition are based on heavy metals such as tin, copper, and zinc; these coatings are toxic to the environment. Recently, environmentally-friendly coatings were developed to inhibit MIC. Among these new coatings, studies have focused on conductive polymers, which have both antibacterial and anticorrosive properties. These conductive polymers have biocidal activity due to the positively charged nitro-groups in their chains. Moreover, due to their good redox properties, these polymers can passivate steel, imparting anticorrosive properties. The biocidal and anticorrosive properties of conductive polymers make them appropriate coatings for MIC inhibition. This study reviews the antibacterial and anticorrosive properties of different types of polymer coating concentrates in environmentally-friendly conductive polymers for inhibition of MIC of steels.