Preparation of a UV anti-aging and superhydrophobic self-cleaning coating by loading nano-rutile on sericite and being modified with HDTMS

To enhance the anti-aging property of a superhydrophobic self-cleaning coating, rutile nano-TiO 2 was loaded onto the surface of sericite via wet grinding method to prepare sericite-rutile composite particles. Then, the composite was modified with hexadecyltrimethoxysilane (HDTMS) and sprayed onto the substrates surfaces to prepare sericite-rutile/HDTMS composite coatings with both UV shielding and superhydrophobic self-cleaning properties. The structure, properties, and mechanism of the coating were studied. The research showed that the micro-nanoscale hierarchical structure has been constructed by compositing sericite and rutile, which were the structure foundation of superhydrophobic coatings. The sericite-rutile composite was modified with HDTMS and sprayed onto the substrates forming a superhydrophobic self-cleaning coating. Water contact angles (WCAs) and slide angles (SAs) of the coating were 155.3° and 1.3°, respectively. The sericite-rutile/HDTMS coating exhibited good UV shielding and anti-aging properties. Its UV shielding rate was 93.53%, which was equivalent to that of pure rutile (94.27%). After UV irradiation for 80 h, the surface maintained superhydrophobicity, and the chromaticity of the coating surface did not change. The superhydrophobicity and low adhesion to water of the sericite-rutile/HDTMS coating are due to the micro-nano hierarchical structure of the sericite-rutile composite and the low surface energy of HDTMS. The UV shielding effect of the coating is mainly due to the strong absorption of UV light by the sericite-rutile composite. This work provides a simple and environmentally friendly method for constructing a coating with UV shielding and superhydrophobic self-cleaning properties.