Preparation and properties of wear resistant thermochromic superhydrophobic coatings

Thermochromic coatings are limited in their practical application due to the surface contamination. One potential solution is to endow the coatings with superhydrophobic self-cleaning properties, but the resulting lack of wear resistance is a central issue that needs to be addressed today. In this study, a new kind of low surface energy nanomaterials were prepared by grafting 1H,1H,2H,2H-perfluorodecyltrichlorosilane on the surface of tetra-needle like ZnO whiskers through chemisorption reaction. A thermochromic superhydrophobic coating was constructed by air spraying with the modified ZnO whiskers and thermochromic microcapsules as functional pigments and silicone resin as film-forming substances. The coating had a highly sensitive gray-white reversible thermochromic performance between 24 ℃ and 30 ℃. The water contact angle reached 158.9° and the sliding angle was only 3°, which could effectively prevent the contamination of dust and other liquids on its surface. Thanks to the mutual penetration and adhesion between the ZnO whiskers, the rough microaggregate structure formed had good robustness and ductility, which endowed the coating with good mechanical stability. The test results showed that the adhesion of the coating reached grade 2, the flexibility was 2 mm and the impact strength reached 25 kg·cm. After 200 wear tests, the surface water contact angle was still greater than 150°. This work provides a feasible solution for modifying thermochromic coatings to achieve wear-resistant superhydrophobicity and improves its application properties in the fields of energy saving, temperature indication and decoration. [Display omitted] •Four needle zinc oxide was modified by chemisorption with FDTS.•A thermochromic superhydrophobic coating with abrasion resistance was prepared.•The coating maintained good superhydrophobic state after a series of mechanical durability tests, showing a long service life.