Self-Assembled Superhydrophobic Coating on the Beryllium Copper Surface with a Micro-Nano Dual-Scale Structure for Anti-icing

Ice formation has long been a major issue troubling the aviation industry, leading to significant energy consumption annually in addressing this problem. Superhydrophobic coatings are an important passive anti-icing strategy. Although beryllium copper alloys are widely used in the aviation field, the superhydrophobic anti-icing coatings reported in the literature primarily use copper as the substrate, with few studies focusing on beryllium copper alloys. In this study, two reactions were employed to construct rough structures at different scales on the surface of beryllium-copper alloy, a material commonly used in the aviation industry. These structures include micrometer-scale acid-etched morphology and needle-like/layered structures with thicknesses in tens of nanometers, as well as a combination of both, forming a dual micro-nano scale structure. This hierarchical dual-scale structure is believed to capture more air upon contact with water droplets, thereby offering excellent superhydrophobicity and anti-icing properties. After surface modification with 1H,1H,2H,2H-perfluorodecanethiol (PFDT), a static contact angle exceeding 165 degrees and a rolling angle as low as 2.9 degrees were achieved on the dual-scale micro-nano surface, along with excellent ice formation delay capabilities, compared to the alloy substrate, the icing was delayed by 1407 s. As a result, water droplets are unlikely to remain on and freeze on this superhydrophobic surface. Based on the experimental results, we have summarized the potential roles of the micro- and nanoscale hierarchical structures. We propose that the microscale rough structures provide higher mechanical strength, effective anti-icing, and anticorrosion properties, while the nanoscale structures contribute to enhanced hydrophobicity and an improved corrosion potential.