Design and Strengthening of Superhydrophobic Coatings: The Influence of Intermediate Layers

The employment of intermediate layer technology to improve the mechanical stability of superhydrophobic coatings (SHCs) is an acknowledged tool, but the mechanism by which intermediate layers, especially different ones, affect superhydrophobic composite coatings is not clear. In this work, a series of SHCs based on the strengthening of the intermediate layer were fabricated by employing polymers with different elastic moduli such as polydimethylsiloxane (PDMS), polyurethane (PU), epoxy (EP) resin, as well as graphite/SiO2 hydrophobic components. Following that, the effect of different elastic modulus polymers as an intermediate layer on the durability of SHCs was investigated. From the perspective of elastic buffering, the strengthening mechanism of elastic polymer-based SHCs was clarified. Furthermore, from the perspective of self-lubrication, the wear resistance mechanism of self-lubricating hydrophobic components in the SHCs was elucidated. Also, the prepared coatings exhibited excellent acid and alkali resistance, self-cleaning, anti-stain, and corrosion resistance. This work confirms that low-elastic-modulus polymers can also play the role of buffering external impact energy by elastic deformation even as an intermediate layer, and provides theoretical guidance for the development of SHCs with robustness.