Fabrication of durable superhydrophobic Mg alloy surface with water-repellent, temperature-resistant, and self-cleaning properties

Superhydrophobic surfaces have superiority in the manufacturing of engineered materials and have attracted considerable interest because of their water-resistant and self-cleaning properties. However, variations in temperature and complex environments limit their use particularly in self-cleaning windows, automobiles, and aircraft body panels. In this work, durable superhydrophobic surfaces were fabricated on a Mg alloy through an electrochemical etching method using NaCl and NaNO3. The contact angle of the superhydrophobic surface was up to 162.1°, and the sliding angle was only 3°. Interestingly, the surfaces were superhydrophobic and thus exhibited excellent water-repellent performance even when impacted by droplets or continuous water jet at a wide range of temperatures. Furthermore, the superhydrophobic surfaces have desirable temperature resistance, which is up to 260 °C owing to the thermal stability of the microstructures and the fluoroalkylsilane (FAS) film. Scanning electron microscopy (SEM) result demonstrates that the microstructures have good thermal stability, and X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectrometry (FTIR) confirm the stable FAS film. The prepared surfaces maintain exceptional self-cleaning properties after alternating-temperature treatment. This work presents a facile strategy for fabricating superhydrophobic surfaces with excellent water-repellent, temperature-resistant, and self-cleaning properties and demonstrates its great potential in practical applications.