A novel two-step strategy to construct multifunctional superhydrophobic wood by liquid-vapor phase deposition of methyltrimethoxysilane for improving moisture resistance, anti-corrosion and mechanical strength

The increased application of wood products has raised new demands for chemically modified wood, such as enhanced water resistance and use of nontoxic fluorine-free compounds, but less attention has been paid to such requirements to date. Herein, superhydrophobic wood (SH-Wood) with high water contact angle (> 150°) and low sliding angle (< 10°) was prepared successfully by using liquid-vapor phase deposition of methyltrimethoxysilane (MTMS) combining vacuum-pressure impregnation and chemical vapor deposition methods for the first time. Covalent grafting of methyl groups with low-surface-energy on SH-Wood substrate was confirmed via Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Scanning electron microscopy (SEM) with energy dispersive X-ray scanning (EDS) analyses showed that the cell wall inside the wood was successfully filled by MTMS in situ grafting and a dense polymethylsiloxane protective layer was formed on the surface of SH-Wood. The SH-Wood generated exhibited excellent moisture resistance, a dramatic decrease in the water uptake (WU) from 116.3 % (control) to 23.5 %, and a diminished water vapor absorption (WVA) from 9.5 % compared to control wood (14.3 %). Moreover, the SH-Wood also demonstrated good anti-corrosion, abrasive resistance, mechanical strength and multi-functions of stain-resistance, anti-adhesion and self-cleaning, which will undoubtedly facilitate greatly expanded applications for wood.