Abstract:
In practical application, affected by chemical corrosion, scratch and wear and other external environment, superhydrophobic coating is easy to aging, cracking and even falling off, resulting in coating failure. Therefore, to solve this problem, a self-healing superhydrophobic surface with weather resistance was designed: Hyperbranched polydimethylsiloxane (PDMS) was used as a flexible substrate and low surface energy material, and nano-silica was introduced to construct the surface rough structure to prepare the superhydrophobic coating. When SiO
2 particle size is 50 nm and solid content is 30wt%, the superhydrophobic coating with contact angle of 154.87° is obtained. The coating shows good mechanical stability after 5 times of tape peeling test. After 10 temperature difference cycling tests and 24 h UV irradiation, the surface contact angle is still greater than 150°, indicating that the coating has good weather resistance. The scratches can be partially healed by heat treatment at 80℃ for 2 h, indicating that the coating has certain self-healing function. At the same time, Tafel and Nyquist test results indicates that superhydrophobic treatment can significantly improve the corrosion resistance of the substrate, and the coating has obvious self-cleaning effect as well. In conclusion, the nano-SiO
2@hyperbranched PDMS composite superhydrophobic coating prepared in this work has self-healing function, which provides a new research strategy for the development of self-healing superhydrophobic coating.