Enhanced efficiency multifunctional coatings for surface protection: The balancing effect of monolithic layered structures

Hydrophobic coatings have been demonstrated to provide effective temporary self-cleaning protection for buildings and artifacts. However, deficiencies in multiple antifouling properties and environmental adaptability hinder the application. Herein, a PDMS/SiO 2 /TiO 2 /Bi 2 SiO 5 /Bi 12 SiO 20 (STB) coating with adhesive matrix-photonic crystal-light driven antifouling composite structure was constructed for multifunctional antifouling protection, which exhibited balanced superhydrophobicity, UV-resistance, antimicrobial, antifouling and self-revealing properties. The coating integrated bonding agent, photonic crystal microspheres and micrometer particles-islands. The bonding agent (PDMS) endowed the coating with a controlled morphology, excellent mechanical properties and favorable environmental adaptability. The photonic crystal layer enhanced the utilization of weak incident light by generating light scattering centers and nonlinear optical effects, which resulted in a coating with excellent UV reflectivity (98 %) while maintaining excellent light-driven stain resistance. This effect resolved the conflict between UV protection and light-driven stain resistance of the coating. Furthermore, the optimal surface roughness of micrometer particle-islands ( R a  = 36.5 nm) provided excellent superhydrophobicity (contact angle = 156.5° ± 1.4°, roll-off angle = 5° ± 0.6°), while it also utilized Bi (3−X)+ and oxygen vacancies (O V ) to enhance the light-driven antimicrobial ( Escherichia coli for 99.0 %, Staphylococcus aureus for 99.3 %) and antifouling activity (Rhodamine B for 96.6 %) of the coating. This study demonstrated a successful balance of desirable properties in antifouling protective coatings and provided a novel strategy for the preparation of temporary protective coatings for buildings and artifacts with multifunctional, all-in-one and self-cleaning properties.