Use of Protective Coatings and Surface Treatments for Long-term Protection

Several kinds of protective coatings have been utilized to protect infrastructures in various environments, including metallic coatings, inorganic and conversion coatings, ceramic coatings, sol–gel/hybrid coatings, and organic coatings. Each coating has specific application requirements, making it critical to identify and select the appropriate coating system for a particular condition. Traditionally, protective coatings protect by creating a physical barrier between the structure and the environment. However, the integrity of this barrier could be compromised by defects or voids due to handling, improper application, unoptimized systems, etc., leading to unexpected failures. It is crucial to be cautious and attentive to these potential failures. Several attempts have been proposed to mitigate this drawback depending on the type of coating. These include the addition of nanomaterials and active agents in organic coatings, elemental ratio and temperature control in metallic coatings, and adjustments in physical and mechanical properties for ceramic coatings. Thus, the chapter will focus on the various types of coatings that have been utilized to provide long-term protection to engineering structures, the strategies used to enhance their performances, application, potential failures, and future perspectives. It also highlights the importance of continuous research and development in this field to improve performance, cost, and acceptability.