Superhydrophobic Surfaces Prepared from Columnar Units by Convenient Electrodeposition with Excellent Mechanical...

Regular array structures prepared by laser processing and three-dimensional printing have promising applications in building stable superhydrophobic structures. However, the size of the materials processed by these two methods is affected by the size of the processing equipment, which prevents the processing of large-size materials. In this paper, a columnar unit consisting of a spherical structure with similar mechanical stability to the array structure is designed and prepared for metal surface protection. A convenient electrodeposition method was used to deposit a layer of columnar micron-sized copper consisting of spheres on the surface of a 6061 aluminum alloy. Subsequently, modified ZrO₂ nanoparticles and polytetrafluoroethylene (PTFE) were sprayed on the surface to form a superhydrophobic surface with synergistic columnar units and ZrO₂ (CAZ). The structure was tested and found to have excellent mechanical stability, maintaining the superhydrophobic properties of the surface even after 200 abrasion cycles of 1000-grit sandpaper under a 500 g load. Moreover, the vertical deformation of the CAZ sample under normal pressure was increased by a factor of 4 compared to the original substrate. Importantly, in subsequent corrosion resistance tests, the CAZ samples showed a two-order-of-magnitude improvement in self-corrosion current density and impedance modulus at low frequencies compared to the original substrate. This strategy is an effective method for preparing mechanically stable superhydrophobic structures that are low-cost and large enough to provide long-term protection for metal surfaces. It is particularly suitable for surface protection of instruments and automotive chassis armor.