Bio-inspired “rigid and flexible” structure design for robust superhydrophobic composite and its application

Abstract

The mechano-chemical-physical robustness is essential for the practical applications of a superhydrophobic coating. However, the superhydrophobic coatings obtained following general design principles hold inherent vulnerability. In this work, inspired by the pangolins’ combination of the rigid armour and the flexible flesh, we propose a new universal “rigid and flexible” design strategy for preparing a superhydrophobic coating with intrinsic mechano-chemical-physical robustness by introducing both rigid and flexible components. As a proof-of-concept, a robust superhydrophobic “rigid and flexible” coating is fabricated using rigid corundum particles and flexible rubber particles. In our design, the rigid component (i.e. corundum particles) provides the protection for the entire structure from mechanical wear, while the flexible component (i.e. rubber particles) endows the structure excellent deformability to eliminate stress under impact, thus having a synergistical advantage in adapting to various mechanical destructions. The as-obtained superhydrophobic “rigid and flexible” coating show superior mechano-chemical-physical robustness against various harsh conditions including 1200 cycles of 2 Kg (40 KPa) linear abrasion, tape-peeling, knife-scratching, water-jetting and chemical corrosion. In addition, the “rigid and flexible” superhydrophobic coating exhibits an excellent weathering resistance and anti-icing properties. Our “rigid and flexible” design strategy will provide a new insight for the development of robust superhydrophobic materials and broaden its application scenarios.