光催化型超疏水自清洁涂层研究现状

光催化型超疏水自清洁涂层是在超疏水涂层的基础上通过物理、化学方法复合光催化材料获得光催化性能，使涂层可以在光照作用下将有机附着物进行分解并通过超疏水表面达到自清洁的效果。本文对国内外光催化型超疏水自清洁涂层的构建方式进行总结，将其归纳为表面构造法、共混法、包覆法3类，构造方法的不同对涂层性能的影响方面也有所区别。与单一功能的超疏水涂层相比光催化型超疏水自清洁涂层更能解决实际应用中所面临的问题。此外，本文对光催化型超疏水自清洁涂层的相关性能进行了横向对比，对影响涂层性能较为关键的耐久性能进行了整体的整理分析，并归纳了目前研究当中的光催化型超疏水自清洁涂层的机械耐磨性、耐腐蚀性、耐冲击性和自愈性能，分析了其耐久性提升机制。最后，对光催化型超疏水自清洁涂层未来的应用前景进行了展望，建议从超疏水-光催化协同作用机制、基底结合强度提升、成本控制和复合涂层自修复等方面对光催化型超疏水自清洁涂层进行研究。

Overview of Photocatalytic Superhydrophobic Self-cleaning Coatings

Photocatalytic superhydrophobic self-cleaning coatings are gaining more and more attention due to their wide and practical application prospects and excellent performance. Photocatalytic superhydrophobic self-cleaning coatings are based on superhydrophobic coatings with photocatalytic materials compounded by physical and chemical methods to obtain photocatalytic properties, so that the coatings can decompose organic adhesives under the action of light and achieve self-cleaning effects through the superhydrophobic surface. In recent years, with more and more scholars conducting research on photocatalytic superhydrophobic self-cleaning superhydrophobic coatings, photocatalytic superhydrophobic self-cleaning coatings have received unprecedented development. And after continuous improvement, the preparation technology of photocatalytic superhydrophobic self-cleaning coatings has become increasingly mature. The article summarized the research status of photocatalytic superhydrophobic self-cleaning coatings at home and abroad, and classified them into three types:surface construction method, co-blending method, and coating method according to their construction methods. The photocatalytic superhydrophobic coatings constructed by the surface construction method could remove pollutants efficiently and had good superhydrophobic properties and were easy to prepare, but the surface layer was too weak, which made the mechanical wear resistance of the coating generally poor and cannot maintain efficient photocatalytic and superhydrophobic properties for a long period of time, and only the superhydrophobic surface obtained by laser etching of the substrate surface showed high mechanical wear resistance. Due to the complicated preparation process, it was difficult to prepare large-area photocatalytic superhydrophobic coatings by the surface construction method; the coatings prepared by the co-blending method could be specially enhanced by material modification to improve the overall durability of the coating, which expanded the application scope of the coating; at the same time, the layer structure could give the coating certain mechanical wear resistance and chemical stability. However, material modification and layer structure construction were complicated, and the preparation of coatings by blending method mainly relied on material properties to ensure coating performance, so it was difficult to enhance the durability of coatings by preparation method alone; The photocatalytic superhydrophobic coatings constructed by coating method had good self-healing properties and mechanical wear resistance, but the response process was long and stability was insufficient, which seriously affected their practical use. It was found that the photocatalytic superhydrophobic self-cleaning coatings were better than the single-function superhydrophobic coatings in solving the problems faced in practical applications. The paper also indicated the development direction and research focus of photocatalytic superhydrophobic self-cleaning coatings in the future. In addition, the performance of photocatalytic superhydrophobic self-cleaning coatings was compared horizontally, and the durability performance, which was the key factor affecting the performance of the coatings, was analyzed. The mechanical wear resistance, corrosion resistance, impact resistance and self-healing properties of photocatalytic superhydrophobic self-cleaning coatings under study were summarized, and their durability enhancement mechanisms were analyzed. The mechanism of constructing a coating with excellent chemical stability was that the material on the surface of the coating would not react violently with strong acids or bases or prevent chemical solutions from immersing inside the coating; It was necessary to construct a hierarchical structure with chemically stable materials to ensure the chemical stability of the coating; The mechanism for constructing photocatalytic superhydrophobic coatings with excellent impact resistance was the same as that for constructing coatings with high mechanical wear resistance, and the rough structure of the coatings should be stable enough; The coating contained materials with pro- and anti-diffusion conversion function under UV irradiation, so that the coating could be self-healed by the pro- and anti-diffusion conversion of the materials under light; The coating could be self-healed by replenishing the materials in the damaged area through microcapsules; The coating structure could be made to have a stable repair structure to ensure that the coating can be self-healed under specific environment. Finally, the future application prospects of photocatalytic superhydrophobic self-cleaning coatings were prospected, and research was suggested in terms of superhydrophobic-photocatalytic synergistic mechanism, substrate bonding strength enhancement, cost control and composite coating self-healing.