Fabrication of a superhydrophobic surface with a hierarchical nanoflake-micropit structure and its anti-icing properties

Herein, we report a novel route to fabricate a robust anti-icing superhydrophobic surface with a hierarchical nanoflake-micropit structure (constructed by a combination of lithography processing and chemical etching methods) on an aluminum substrate. Moreover, the superhydrophobicity and icephobicity were systematically explored based on a comparative study with different structured surfaces prepared under four different processing conditions. Results indicated that the icephobicity and superhydrophobicity of the hierarchically structured surfaces were superior to those of the single-structured surfaces, and the superhydrophobic hierarchically structured surface exhibited high non-wettability, with an apparent contact angle as high as approximately 173° and a sliding angle as low as about 4.5°. In addition, for this surface, ice adhesion strength was greatly reduced to 75 kPa. Therefore, we reasonably believe that the superhydrophobic surface with a hierarchical nanoflake-micropit structure possesses an excellent water repellency and excellent anti-icing properties, displaying an ideal platform for applications in the aviation industry.