Preparation of superhydrophobic coatings with excellent mechanical and chemical stability by one-step spraying method with selected fluorine-free modifiers

Superhydrophobic coatings have great potential for applications in daily life and industrial production. In practical applications, however, the excellent mechanical and chemical stability of superhydrophobic surfaces remains a challenge. In this paper, a one-step spraying method, simple in process and low cost, was used to prepare superhydrophobic materials. To investigate the effect of different types of non-fluorinated modifiers on the wettability of the coatings, four silane non-fluorinated modifiers, dodecyltrimethoxysilane, hetradecyltrimethoxysilane, octadecyltrimethoxysilane and polydimethylsiloxane, were selected to prepare superhydrophobic surfaces. The superhydrophobic coating modified by non-fluorinated modifier retained its superhydrophobic performance after 48 h immersion in strong acid, strong alkali and salt solution and 6 months in outdoor environment, with excellent corrosion resistance. Moreover, it showed superior abrasion resistance and durability in sandpaper abrasion and tape peeling cycles tests. The superhydrophobic coating prepared by PDMS had the best overall performance compared with other silane non-fluorinated modifiers, and the separation efficiency of the prepared superhydrophobic cotton fabric could still be maintained above 99 % after 20 oil–water separation cycles. Its water contact angle was 164.8° and sliding angle was 2.3°, and it had the highest first bouncing height after the droplet bouncing test.