Cao Huimin, Guo Xi, Zhou Yongdong, Yan Yutao, Sun Weisheng
Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, People's Republic of China.
School of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou 311300, People's Republic of China.
ACS Omega. 2022 May 17;7(21):17921-17928. doi: 10.1021/acsomega.2c01215. eCollection 2022 May 31.
To improve the hydrophobicity of precious hardwood, a facile sanding pretreatment and alkyl ketene dimer (AKD) modification were performed. After the AKD modification, the wood was highly hydrophobic, and the contact angle was 143°. The increased hydrophobicity could be attributed to the ester bond formed between the wood hydroxyl groups and AKD, which was confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy. Sanding pretreatment could further greatly increase the wood hydrophobicity and render it superhydrophobic, not only in a cross-section but also in the tangential and radial sections. The changed wood surface roughness could be responsible for the increased hydrophobicity, which was confirmed by characterization with a scanning electron microscope (SEM) and a three-dimensional optical microscope. Apart from the improved hydrophobicity, the AKD-modified wood exhibited excellent water, acid, and toluene resistance. After a 12 h immersion, the contact angle did not change significantly, and the acid immersion contributed to an improvement in the hydrophobicity of the wood. Furthermore, the resultant AKD-modified wood exhibited an excellent self-cleaning effect.
为提高珍贵硬木的疏水性，进行了简便的打磨预处理和烷基烯酮二聚体（AKD）改性。经过AKD改性后，木材具有高度疏水性，接触角为143°。疏水性的提高可归因于木材羟基与AKD之间形成的酯键，衰减全反射傅里叶变换红外光谱证实了这一点。打磨预处理不仅可以在横截面，还可以在弦向和径向截面进一步大幅提高木材的疏水性并使其具有超疏水性。木材表面粗糙度的变化可能是疏水性提高的原因，扫描电子显微镜（SEM）和三维光学显微镜的表征证实了这一点。除了疏水性提高外，AKD改性木材还表现出优异的耐水、耐酸和耐甲苯性能。浸泡12小时后，接触角没有明显变化，酸浸泡有助于提高木材的疏水性。此外，所得的AKD改性木材表现出优异的自清洁效果。
