Wood Surface-Embedding of Functional Monodisperse SiO₂ Microspheres for Achieving Robust, Durable, Nature-Inspired, Programmable Superrepellent Interfaces

Abstract

Nature-inspired, robust, durable, liquid-repellent interfaces have attracted considerable interest in the field of wood biomimetic intelligence science and technology application. However, realizing green environmental protection and low maintenance and replacement cost wood surfaces constructed with micro/nanoarchitectures is not an easy task. Aiming at the problem of poor waterproof performance of wood, a silicon dioxide/ polydimethylsiloxane (SiO 2 /PDMS) self-cleaning programmable superhydrophobic coating was biomimetically constructed on the wood substrate by surface-embedded dual-dipping design based on the "substrates + nanoparticles" hybrid principle of the lotus leaf effect. This robust, durable, nature-inspired, self-cleaning, programmable superhydrophobic coating was found to have no observable impact on the original color and texture of the natural wood. The SiO 2 /PDMS/wood prepared exhibited exceptional liquid repellency and a high static water contact angle (WCA) of 158.5°and a low slide angle (SA) of 10°, including everyday generalpurpose droplets, indicating that the introduction of the monodisperse SiO 2 microspheres can effectively enhance the superhydrophobic properties of the hydrophilic wood. We applied this strategy to a variety of substrates, including wood-cellulose aerogel and wood-cellulose paper, and demonstrated that the liquid-repellent nature of the self-cleaning superhydrophobic coating remained unchanged. Moreover, the superhydrophobic surface of SiO 2 /PDMS/wood was preserved even after harsh abrasion conditions, including mechanical damage (sandpaper, sharp steel blade, and tapes), thermal damage (UV irradiation and low/hightemperature exposure such as steaming and freezing), chemical damage, and solvent corrosion (immersion in acid, alkali), demonstrating robust stability of the superhydrophobic coating. Furthermore, the SiO 2 /PDMS programmable superhydrophobic coating exhibits exceptional exciting self-cleaning and stain-resistant properties, making it offer greater possibilities in terms of scientific challenges and real-world problem-solving at biomimetic smart superhydrophobic interfaces in wood.