Preparation of superhydrophobic/oleophobic wood coating with fluorinated silica sol by a simple spraying method

Abstract

The biomimetic construction of superhydrophobic coatings on wood surfaces significantly reduces the water absorption capacity of wood while enhancing its deformation resistance, thereby extending the service life of wooden structures. In this work, a fluorinated silica sol was prepared from alkaline silica sol and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (PFDMS), and evenly sprayed over the wood surface to effectively produce superhydrophobic/oleophobic wood specimens. The effect of the preparation procedure of fluorinated silica sol on the wettability of the coating was investigated. Acid and alkali corrosion tests were conducted to assess the chemical stability of the superhydrophobic coating, while sandpaper abrasion tests were used to evaluate its mechanical stability. The results showed that with a volume ratio of silica sol to PFDMS of 6:1 and a reaction period of 30 min, the modified wood exhibited excellent superhydrophobicity, with a water contact angle of 157.3° and an oil contact angle of 126.5°. Furthermore, the superhydrophobic coating demonstrated excellent mechanical and chemical durability, along with self-cleaning properties. These findings have significant practical implications for enhancing the performance and longevity of wood.