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Reducing the hydrophilic nature of wood could enhance dimensional stability and improve life cycle performance. Masson pine and pecan wood were modified to create superhydrophobic, self-cleaning functions by spray-coating with Cu2O nano-particles (Cu2O NPs)/phenol formaldehyde (PF) resin mixed solution followed by immersion in a stearic acid ethanol solution. Two types of Cu2O NPs, derived from different concentrations of copper chloride (CuCl2) were evaluated for their ability to improve hydrophobicity of wood surface. A special petal-shaped structure on the edge of Cu2O NPs was found on modified pecan wood, and water contact angles (WCA) of both kind of modified wood reached around 155° and sliding angles (SA) less than 10°. Meanwhile, low liquid permeability and excellent repellency to aqueous solutions with pH = 1 to 13 were achieved. The critical WCA around 150° was also maintained on modified wood surfaces after being immersed in strong acid (pH = 2) and strong alkali (pH = 12) solutions for 12 h. Furthermore, remarkable mechanical durability was obtained after harsh abrading test, which could be attributed to the high bond strength from cured PF resin adhesive. Such highly waterproof, acid/alkali resistant and hard-wearing superhydrophobic surface must have potential to be widely applied in wood products industry.

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Sustainable wood-based materials with versatile functions such as ultraviolet resistance, superhydrophobicity, selfcleaning/antifouling capability, etc. have great potential to be used in building fields for replacing non-biodegradable fossil-based materials due to their facile preparation, biodegradability, and durability as well as the increasing concerns on environmental impact. Herein, pine-cone-shaped Cu 7 Cl 4 (OH) 10 •H 2 O nanoparticles were in situ synthesized by a hydrothermal process on a radial section of a poplar scrimber surface. As expected, the superhydrophobic function had been endowed to all three sections of the poplar scrimber surface, which exhibited excellent mechanical durability, desirable chemical stability, and splendid self-cleaning and antifouling capabilities. It should be noted that the modified poplar scrimber kept the superhydrophobic state even after 624 h of exposure to 340 nm ultraviolet (UV) irradiation, which could be ascribed to the unique hierarchical structure of the pine-cone-shaped Cu 7 Cl 4 (OH) 10 •H 2 O nanoparticles toward providing abundant voids for absorption of UV light. More importantly, a model of crystalline cellulose before and after compression was proposed to explain the improvement of physical and mechanical properties of poplar scrimber. This work will provide a new path for the superhydrophobic modification on wood-based engineering materials, which has potential to be applied in the industrial production of superhydrophobic wood scrimber to promote the sustainable development of timber resources.