Texturing commercial epoxy with hierarchical and porous structure for robust superhydrophobic coatings

The practical application of superhydrophobic coatings is restricted majorly by stability issues, especially in such cruel conditions as acid rain, pollutant contamination, and mechanical abrasion. In this work, we demonstrated a new type of superhydrophobic coatings with remarkable robustness and versatility using commercial epoxy as main building block. The hierarchical and porous structure was achieved by texturing micrometer-sized pores on the adhesive coatings, in which the SiO2 nanoparticles were embedded. Due to strong substrate adhesion, excellent internal bonding, and micropore cushioning, the as-prepared superhydrophobic adhesive coatings can avoid the consumption of hierarchical structure after each abrasion and tightly anchor itself on substrate as well as soften the pressure during the mechanical force acting on them. The synergistic effect of these three protection mechanisms contributes to preferable mechanical robustness under severe sandpaper abrasions, cyclic tape peels, and knife scratches. This functional coating also can remain superhydrophobic after long-term exposure to a large variety of media, including corrosive solutions, daily consumed liquids, and water at different temperatures. Simultaneously, the epoxy resin has good compatibility with both hard and soft substrates, and thus providing such superhydrophobic adhesive coatings with high versatility for the applications in advanced functional materials. The concept of transforming commercial adhesive into superhydrophobic surface provides a simple and versatile approach to highly robust superhydrophobic materials.