A one-stone-two-birds tactic: Pyrolysis-driven durable superhydrophobic wood/bamboo with photothermal effect for outdoor ice prevention

As a renewable building material, wooden material is susceptible to frost and icing when exposed to harsh outdoor conditions, which not only severely affects the service life of wood but also cause significant safety hazards. Constructing superhydrophobic wooden surfaces with photothermal functions is an effective way to delay droplet freezing and ice accumulation. However, this modification strategy always involves complex preparation processes, and the durability of these superhydrophobic wooden surfaces is unsatisfactory. In this work, a one-stone-two-birds tactic to construct durable superhydrophobic wood/bamboo surface with photothermal effect was proposed. By thermally decomposing wood pre-coated with a polydimethylsiloxane/hydroxyapatite nanospheres (PDMS/HAP) layer, PDMS was converted into silica nanoparticles with silane on the surface, and a carbon layer with photothermal conversion properties was formed on the wooden surface. The simultaneous generation of hydrophobic silica nanoparticles and a carbon layer endowed the wood/bamboo surface with durable superhydrophobic properties and photothermal conversion capabilities. This method can be applied to various wood species and bamboo. The obtained wooden superhydrophobic surface exhibited a water contact angel of 160.5°, and has excellent durability. This superhydrophobic surface could not only withstand physical abrasion such as sandpaper abrasion and water impact, but also maintain its superhydrophobicity after exposure to chemical corrosion and UV irradiation. This superhydrophobic layer also provided the wooden materials with good dimensional stability and moisture resistance. In addition, the photothermal conversion effect enabled the wood surface to rapidly rise to 55.3 °C under one sun illumination, and ice crystals slid off its surface within 8 s. This work presents a simple and promising strategy for constructing photothermal and superhydrophobic layer on wood/bamboo surface, and is expected to mitigate the frosting and icing problems of wooden building materials in cold conditions and extend their service life.