Spontaneous formation of a nest-like frame structure in sprayed coatings for superhydrophobic applications

Abstract

The accretion of ice, contaminants, oxidants, and organisms on exposed surfaces has been a perpetual concern in many fields of engineering and often presents a serious safety hazard. Green methods to make superhydrophobic (SH) coatings via spraying nanoparticles are attracting routes to resolve these issues, especially considering the low energy inputs and capital costs. However, these nanoparticle coatings do not yet meet the demanding standards of practical applications. Here, we show that spraying SiC whiskers (SiCw) with optimized dispersity in water spontaneously forms nest-like frame structures that readily host hydrophobic nanoparticles (NPs), yielding SH coatings with excellent durability and usability. The SiCw frame structure improves the wear resistance of the NPs coating by two orders of magnitude and withstands repeated bending and twisting (180°), making it more appealing than the state-of-the-art SH surfaces fabricated by sophisticated techniques. Exhibiting a low surface friction coefficient, superior hardness, and adequate adhesive strength and fracture toughness, the SiCw frame structure endows our novel SiCw/NPs composite coating with the necessary properties to meet the stringent demands for efficient SH coating fabrication.