Development of a versatile coating based on hydrolysis-assisted self-bonding and structure evolution of aluminum nitride nanopowder: Application toward repairing severe damages on superhydrophobic surfaces

As superhydrophobic surfaces have emerged as powerful tools to improve performance and impart new functionalities in various industrial applications, many attempts have been devoted toward the sustenance of the surfaces by overcoming their vulnerabilities to mechanical damage and abrasive wear. Although the representative strategies to improve the durability of superhydrophobic surfaces by employing unique microscale structures or using self-healing materials have been attracting considerable interest, they are limited by issues such as the need for thermodynamic stimuli or limited repairability depending on healing materials. To overcome these, in this study, we report a versatile coating method applicable toward the selective repair of severe damages on superhydrophobic surfaces by constructing surface structures based on electrophoretic deposition and hydrolysis of aluminum nitride (AlN) nanopowders without using any binder resin. Furthermore, by using a water-soluble adhesive as a temporary protective layer for electrophoretically deposited AlN powders, hierarchically structured aluminum hydroxides with excellent adhesion to various electrically conductive substrates were uniformly developed. These features enable the successful repair of the wettability of partially and severely damaged samples, which can extend the short service life and broaden industrial application scope of superhydrophobic surfaces. [Display omitted] •Hierarchical structures for superhydrophobic surfaces were prepared by self-bonding and structure evolution of AlN nanopowders.•A novel method to protect temporarily the electrophoretic deposited layer during hydrolysis reaction is proposed.•The resulting coating layer shows excellent adhesion to various substrate materials.•The coating can be applied to repair selectively damaged areas on the superhydrophobic surface.