Versatile nonfluorinated superhydrophobic coating with self-cleaning, anti-fouling, anti-corrosion and mechanical stability

Abstract

It remains a great challenge to design and achieve fluorine-free superhydrophobic materials for multifunctional applications through facile and substrate-independent approaches. Herein, environmental-friendly superhydrophobic composite coating was fabricated with the combination of nano zinc oxide (nano-ZnO) and polydimethylsiloxane (PDMS) via a versatile spray-coating method. The surface wettability, micro-nano morphologies and chemical compositions of the superhydrophobic ZnO@PDMS coating were investigated through contact angle meter, FE-SEM, AFM, EDS, XPS and FTIR techniques. The optimal superhydrophobic ZnO@PDMS coating with water contact angle (WCA) of 158.3 ± 1.7° and sliding angle of 6.2 ± 1.8° can be achieved with the nano-ZnO/PDMS mass ratio of 1.5:1. The self-cleaning and anti-fouling ability was evaluated based on the solid and liquid contaminants. The electrochemical impendence spectroscopy (EIS) results verified that the superhydrophobic ZnO@PDMS coating exhibits a larger capacitive arc diameter, enhanced charge transfer resistance and |Z|0.01 Hz value at the low frequency, suggesting an improvement of anti-corrosion performance. Besides, the mechanical robustness and stability of the superhydrophobic ZnO@PDMS coating were evaluated through tape-peeling and sandpaper abrasion tests, which provides potential applications towards real-world applications.