Natural light-induced self-healing antibacterial superhydrophobic coatings based on ODA/Ag-PDA@HMS-ODA

[Display omitted] •A multifunctional superhydrophobic coating is prepared through a straightforward large-scale spraying technique.•This coating demonstrates superior photothermal self-healing characteristics.•It possesses outstanding self-cleaning properties and mechanical-chemical stability. Self-healing superhydrophobic coatings have garnered widespread attention in recent years. However, developing rapid, multi-cycle, and multifunctional self-healing superhydrophobic coatings remains a significant challenge. In this study, we designed and synthesized a core–shell structured porous nanosphere with hollow mesoporous silica (HMS) as the core, loaded with octadecylamine (ODA) inside, and coated with polydopamine (PDA) on the HMS surface. Finally, nanosilver (AgNPs) and ODA were loaded on the outer surface, and the resulting material was formulated into a new type of sunlight-responsive, self-healing, and antibacterial coating via an adhesive. This coating exhibits multi-cycle and rapid self-repair properties under sunlight exposure and achieves superhydrophobicity (WCA = 157.3°). The multi-cycle self-healing process is mainly attributed to the large specific surface area of HMS (with a specific surface area of 521.27 m2/g), which allows for the loading of more low surface energy ODA. Additionally, due to the low melting point of ODA and the synergistic photothermal effect of PDA and AgNPs, ODA can migrate to the damaged surface more quickly, endowing the coating with faster self-healing capabilities. Moreover, the prepared coating also possesses excellent antibacterial properties, ensuring a reduction in biological contamination and extending the service life of the superhydrophobic coating.