Wood-based nanocomposite via in-situ formation of organic/inorganic hybrid porous polymer for robust superhydrophobicity and sustainable radiative cooling

Abstract Bio-based radiative cooling materials hold significant application potential in carbon-free passive cooling but suffer from performance loss due to dust accumulation and rainwater washing. Superhydrophobic surfaces can enhance self-cleaning and durability, yet poor abrasion resistance often compromises superhydrophobicity. Herein, we develop a wood-based nanocomposite by infiltrating a highly porous and low-surface-energy copolymer and SiO2 nanoparticles into a delignified wood scaffold. The resulting nanocomposite achieved satisfactory radiative cooling performance, with a solar reflectance of 91.29% and infrared emissivity of 98.77%, yielding a sub-ambient cooling of 8.36 °C and potential energy savings of 32.27 MJ/m2 in cooling energy consumption in China’s hottest regions. Furthermore, even after rigorous environmental testing, including 3000 abrasion cycles, water washing, and solvent immersion, the nanocomposite still maintained exceptional superhydrophobicity (contact angle > 160°, rolling angle < 4°). More importantly, the wood-based nanocomposite retained approximately 80% of its cooling capability after rigorous environmental testing. This work provides practical solutions to the two questions of inadequate abrasion resistance in bio-based superhydrophobic materials and poor long-term performance of bio-based radiative cooling materials, which is of great significance and value for the high-value application of bio-based functional materials.