Durable and Flexible Superhydrophobic Materials: Abrasion/Scratching/Slicing/Droplet Impacting/Bending/Twisting-Tolerant Composite with Porcupinefish-Like Structure

Abstract

Superhydrophobic materials with micro/nanotextured surface have attracted tremendous attention owing to their potential applications such as self-cleaning, antifouling, anti-icing, and corrosion prevention. Such a micro/nanotextured surface is a key for high water repellency. However, such a texture is fragile and readily damaged when the material is deformed, scratched, or sliced off. Thus, it is challenging to develop superhydrophobic materials that can sustain high water repellency after experiencing such a mechanical deformation and damage. Here we report abrasion/scratching/slicing/droplet impacting/bending/twisting-tolerant superhydrophobic flexible materials with porcupinefish-like structure by using a composite of micrometer-scale tetrapod-shaped ZnO and poly­(dimethylsiloxane). Owing to the geometry of the tetrapod and elasticity of poly­(dimethylsiloxane), the composite material exhibits stable water repellency after 1000 abrasion and 1000 bending cycles, or even after their surfaces were sliced off many times. The material maintains superhydrophobicity even under a mechanically deformed state such as bending and twisting. The materials can be painted on a variety of substrates and molded into desired shapes and used in a myriad of applications that require superhydrophobicity.

Directional Transportation of Impacting Droplets on Wettability-Controlled Surfaces

“…[1][2][3][4][5] As a droplet-surface interaction phenomenon, the droplet impacting is affected by surface structures and wettability greatly, presenting various outcomes including deposition, splashing, and rebound. [6][7][8][9][10] Specially, the rebound of droplets when impacting on nanoengineered superhydrophobic surfaces has attracted numerous attention in recent decades, [11][12][13][14][15] as it has promising applications in various engineering fields such as anti-icing, self-cleaning, and fluid transportation. [16][17][18][19][20][21] For droplet impacting on a superhydrophobic surface, the contact time, i.e., the rebound time, is a key factor which influences the practical application significantly.…”

Facile Formation of Hierarchical Textures for Flexible, Translucent, and Durable Superhydrophobic Film

“…Compared with most of the flexible and superhydrophobic bulk materials, the presented film can be more adaptive to surfaces with a broader range of curvature and specific shape, such as the exterior with small radius or the one with sharp angles. [ 29–32 ] As presented in Figure 1f, the superhydrophobic film, which was closely attached to the index finger, could still maintain the low‐adhesive capability even under the bending/stretching status. Video S1 in the Supporting Information also records the mechanical stability of the as‐prepared film when attaching to the finger during the bending and stretching.…”

“…[ 29 ] Recently, a porcupinefish‐like structured flexible material was developed with abrasion/scratching/droplet impacting/bending/twisting‐tolerant superhydrophobicity based on micrometer‐scale tetrapod‐shaped ZnO and poly(dimethylsiloxane). [ 30 ] Even sorts of elastic monoliths have recently been realized with optimized robustness against abrasion, the flexibility and limited stretchability of such bulk materials still impose inevitable restriction of adaptability toward broad applications. [ 31,32 ] Compared with the bulk materials, flexible films with compact thickness are more attractive due to the intrinsic superiority, namely, the adaptability for surfaces of irregular shapes or large curvature.…”

Highly Robust, Pressure‐Resistant Superhydrophobic Coatings from Monolayer Assemblies of Chained Nanoparticles

“…Therefore, the film can remain superhydrophobic even when the top layers are removed. [ 24 ] However, accompanied with large thickness is increased light scattering and thermal resistance due to increased solid‐air interface and air volume. In other words, thick superhydrophobic coating would adversely decrease the transparency of glass panels and the heat transfer efficiency of fins of air conditioner or water collectors.…”