Facile fabrication of wear-resistant, fluorine-free, strongly adhesive superhydrophobic coating based on modified SiO2/silicone nanocomposites

The implementation of conventional superhydrophobic surfaces (SHPOs) preparation method on a broad scale is constrained by its complexity, low wear resistance, as well as its reliance on potentially harmful fluorine-containing chemicals, etc. Herein, a wear-resistant, fluorine-free, strongly adhesive superhydrophobic composite surface was fabricated by applying the one-step spraying method. The superhydrophobic surface consisted of modified SiO2 particles, commercial silicone paint, and a vinyl-capped epoxy polysiloxane (VEPS) which was synthesized as an adhesion promoter. The prepared coating exhibits a water contact angle (WCA) of 164.9 ± 1.3° and a sliding angle (SA) of 4.1 ± 0.6° with 30 wt% of modified SiO2, which provides the optimum trade-off between hydrophobicity and robustness. The superhydrophobic mechanism of the coating was elaborated based on its surface morphology. Moreover, the coating was subjected to various performance tests. After 12 h of immersion in solutions with different pH values, 26 linear wear tests or finger touch tests, the coating still exhibited superhydrophobicity, which indicates that it possessed excellent chemical durability and good abrasion resistance. Meanwhile, the coating still maintained a high water repellency when it had been subjected to tape peeling cycles, high temperature stability test or boiling water durability test. This facile approach to fabricate superhydrophobic surfaces greatly enhances the potential applicability of these coatings.