Recent achievements and applications of photothermal self-healing coatings: A review

In recent years, the development of intelligent self-healing coatings has become one of the frontier research hotspots in the field of corrosion and protection. These innovative coatings are designed to autonomously repair themselves when damaged by external factors, thus reinstating their corrosion-resistant capabilities. The integration of photothermal materials has led to the development of light-triggered self-healing coatings. These coatings are capable of detecting surface flaws, such as cracks and scratches, and utilize light-induced physical and chemical reactions to repair these imperfections, enhancing their protective longevity. The precision, rapid response, and wide operational range of photothermal self-healing technologies point to a multitude of potential applications. This review provides a comprehensive overview of the latest advancements and challenges in photothermal self-healing coatings, organized into four sections. Firstly, it explores three types of photothermal self-healing coatings: those relying on external supplements, and those based on dynamic covalent and non-covalent interactions. It delves into the preparation, characterization, and fundamental properties of these coatings. Secondly, the paper reviews self-healing coatings based on different photothermal materials, focusing on carbon materials, semiconductor materials and organic materials. Thirdly, it examines the potential applications of different photothermal self-healing coatings in areas such as anticorrosion coatings, antibacterial coatings and electronic devices. Finally, the paper discusses future directions in this field and highlights some critical unresolved challenges.