Robust superhydrophobic micro-nanostructures design based on polarity-opposite amorphous polymers

Abstract

Superhydrophobicity exhibited by several natural surfaces has broad application prospects due to their excellent self-cleaning and low adhesion properties. However, designing a robust superhydrophobic coating via design strategy using amorphous polymers is allimportant for industrial applications, yet rather challenging. Here, we report a scalable strategy based on the phase separation and swelling treatment to construct an ultra-durable superhydrophobic coating with hierarchical micro-/nanostructures formed by two amorphous polymers (e.g. hydrophilic and lipophilic polymers). The controlled phase separation of two amorphous polymers creates uniformly distributed microprotrusions on the coating surface and the following swelling process produces submicro-/nanobumps on the microprotrusions. Notably, when both types of polymers achieve the hierarchical micro-/nanostructures, hydrophilic polymers exhibit strong adhesion with the substrates, whereas lipophilic polymers reduce the surface energy of the system. Benefitting from the self-similar structure and the adhesive effect, the polymer-based superhydrophobic coating displays superior mechanical and chemical robustness. Furthermore, our strategy will boost the practical application of robust superhydrophobic coatings for anti-corrosion application.