Superhydrophobic Poplar Scrimber Via In Situ Synthesis of Cu7Cl4(OH)10·H2O Heterostructure Inspired by Pine Cone with Superultraviolet Resistance

Sustainable wood-based materials with versatile functions such as ultraviolet resistance, superhydrophobicity, self-cleaning/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 Cu7Cl4(OH)10·H2O 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 Cu7Cl4(OH)10·H2O 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.