Improving the artificial weathering properties of heat-treated wood by using magnetron sputtered ZnO-PDMS coating

Abstract To resolve the surface color variance and cracks in heat-treated wood induced by environmental factors such as light and water, the magnetron sputtered coating method was used to modify heat-treated wood in this study. The effects of four modification strategies in terms of pure PDMS (polydimethylsiloxane), pure magnetron sputtering ZnO, PDMS-ZnO (PDMS coating followed by ZnO sputtering), and ZnO-PDMS (ZnO sputtering followed by PDMS coating) on the wettability and anti-aging properties of heat-treated wood surfaces were compared. The morphology and chemical composition of the modified wood before and after aging were studied using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy to reveal the modification mechanism. The results showed that the four coatings were successfully loaded onto the wood surface. After 360 h of artificial aging, the surface of the heat-treated wood coated with ZnO-PDMS retained its original structure with no cracks, warping, or other damages. The PDMS coating effectively prevented the invasion of wood by water and reduced the loss of the ZnO particles sputtered on the wood surface, thereby enabling ZnO to provide long-term UV shielding. After aging, the equilibrium contact angle reached 133°, while the color difference (ΔE*) was 2.72, indicating good hydrophobicity and light-aging resistance.