Bioinspired preparation of regular dual‐level micropillars on polypropylene surfaces with robust hydrophobicity inspired by green bristlegrass leaves

Abstract

The fine microstructure on the natural green bristlegrass leaf of Setaria viridis (L.) Beauv, which exhibits a contact angle (CA) of 155 ±2 and a rolling angle (RA) of 79 ±2 , is carefully observed. Based on the understanding of the underlying mechanisms for superhydrophobicity and moderate surface adhesion, an efficient replica molding strategy is proposed for mimicking the microstructures on green bristlegrass leaf surface to polypropylene (PP) surfaces. The bioinspired PP replica with dual-level micropillars are molded by using the unitized template of steel Meshes A and B. Interestingly, the PP replica inherits both hydrophobicity and adhesion of the natural leaf. Furthermore, the PP replica can stabilize its hydrophobic state under a 980 Pa external pressure, which is attributed to the composite Cassie-Wenzel mixed wetting state on the microstructured interface. The CA comparatively goes down and RA increases, resulting in superhydrophobic surface with moderate adhesion on the bioinspired surface. Hence, the microstructures and hydrophobicity are successfully replicated to the PP surface by only using the low cost, available and reliable steel meshes in the bioinspired replica molding process. K E Y W O R D S green bristlegrass, bioinspired, replica molding, robust, hydrophobicity

One-step laser etching of a bionic hierarchical structure on a silicone rubber surface with thermal and acid/alkali resistance and tunable wettability

“…Therefore, the modified surface has a stable contact time and a full droplet rebound behavior. 50 The robust dynamic wetting state and quick rebound properties are conducive to practical engineering involved in outdoor applications.…”

Direct laser etching of hierarchical nanospheres on silicon rubber surface with robust dynamic superhydrophobic stability

“…However, no significant change in the contacting time for the droplets with different impacting speed is found, nanoscale air pockets trapped below the hierarchical nanospheres (Figure 4(b),(c)) keep the water droplets from infiltrating the bottom of the inter‐nanosphere areas until the droplet rebound from the surface (Figure 4(d)). So, the stabilized contact time (~12 ms) and robust dynamic superhydrophobicity are induced on the modified silicone rubber surface 27 . Undoubtedly, these properties are beneficial to practical engineering, such as anti‐icing and self‐cleaning associated with outdoor insulation.…”

“…So, the stabilized contact time (~12 ms) and robust dynamic superhydrophobicity are induced on the modified silicone rubber surface. 27 Undoubtedly, these properties are beneficial to practical engineering, such as antiicing and self-cleaning associated with outdoor insulation.…”

Scalable superhydrophobic coatings with recycled polypropylene

“…This phenomenon is a result of both surface chemistry and surface architecture, such as surface energy and micro-nano scale surface roughness. 1 c ,2 The fabrication of superhydrophobic surfaces presents practical challenges, primarily linked to the selection of precursors, substrates, and techniques to achieve the desired surface morphologies. Reported methods include perfluoro silane grafting, 3 nanoparticles coating, 4 polymer solution coating, 5 moulding from textured template, 6 and deposition of precursors using pulsed laser techniques.…”

“…3–7 Some polymer surfaces are designed to replicate the hierarchical micro/nanostructures found in natural superhydrophobic surfaces, such as lotus leaves and cicada wings. 1 c , d ,2,9 One notable example involves the synthesis of microspheres with nano-scaled rough surfaces using a block copolymer of polypropylene and poly(methyl methacrylate) (PP-PMMA). 10 These microspheres exhibit remarkable superhydrophobicity, with water contact angles reaching up to 160°.…”