Trifolium repens L.-Like Periodic Micronano Structured Superhydrophobic Surface with Ultralow Ice Adhesion for...

Wind turbine blades are often covered with ice and snow, which inevitably reduces their power generation efficiency and lifetime. Recently, a superhydrophobic surface has attracted widespread attention due to its potential values in anti-icing/deicing. However, the superhydrophobic surface can easily transition from Cassie-Baxter to Wenzel at low temperature, limiting its wide applications. Herein, inspired by the excellent water resistance and cold tolerance of Trifolium repens L. endowed by its micronano structure and low surface energy, a fresh structure was prepared by combining femtosecond laser processing technology and a boiling water treatment method. The prepared icephobic surface aluminum alloy (ISAl) mainly consists of a periodic microcrater array, nonuniform microclusters, and irregular nanosheets. This three-scale structure greatly promotes the stability of the Cassie-Baxter state. The critical Laplace pressure of ISAl is up to 1437 Pa, and the apparent water contact angle (CA) is higher than 150° at 0 °C. Those two factors contribute to its excellent anti-icing and deicing performances. The results show that the static icing delay time reaches 2577 s, and the ice adhesion strength is only 1.60 kPa. Furthermore, the anti-icing and deicing abilities of the proposed ISAl were examined under the environment of low temperature and high relative humidity to demonstrate its effectiveness. The dynamic anti-icing time of ISAl in extreme environments is up to 5 h, and ice can quickly fall with a speed of 34 r/min when it is in a horizontal rotational motion. Finally, ISAl has excellent reusability and mechanical durability, with the ice adhesion strength still being less than 6 kPa and the CA greater than 150° after 15 cycles of icing-deicing tests. The proposed structure would offer a promising strategy for the efficient anti-icing and deicing of wind turbine blades.