层层自组装SiO2/木材复合材料的超疏水性及其形成机制∗

摘要

The superhydrophobic wood surface was fabricated by layer-by-layer assembly of silica (SiO2 )nanop-articles and subsequent modification with 1 H,1 H,2 H,2 H- perfluoroalkyltriethoxysilane (POTS)reagent.After the characterizations of EDXA,FT-IR,XRD and SEM,the self-assembled SiO2 nanoparticles have chemically combined with the subsequent modified POTS molecules on the wood surface.The water contact angle (WCA) test shows that the superhydrophobic wood surface reached since self-assembly 5 layers with one of the highest WCA of 1 6 1°.TG analysis shows that the superhydrophobic wood has good thermal stability.The formation mechanism of the superhydrophobic wood surface in this study could be explained by the combination of the high surface roughness of SiO2 nanoparticles and the low surface free energy film of POTS on wood surface.%通过层层自组装技术制备纳米 SiO2薄膜,利用1 H,1 H,2 H,2 H-全氟辛基三乙氧基硅烷(POTS)作为疏水改性剂制备出了超疏水木材.EDXA、FT-IR 、XRD、SEM分析证实经过层层自组装处理后,木材表面生长出了纳米SiO2薄膜,后续修饰处理的POTS试剂后与纳米SiO2通过化学键结合生长于木材表面.接触角测试显示,当木材表面自组装5层后,制备的木材具有超疏水性能,接触角高达161°.TG分析表明超疏水木材具有较好的热稳定性.超疏水木材表面的形成机制可以归纳为层层自组装的纳米Si O 2薄膜在木材表面构建了微纳米级粗糙结构,并经后续低表面能物质POTS的修饰处理使得木材表面由亲水转变为超疏水.