基于有机硅烷在木材表面的分子自组装及其对木材润湿性的调控机理

The greatest disadvantage of wood in actual applications is its hygroscopicity; hydroxyl groups on the porous surface readily form hydrogen bonds with sorbed water molecules. Therefore, the effective method for the efficient utilization of wood is to fabricate amphiphobic wood surfaces in order to prevent them from adsorbing the atmospheric moisture and oil contaminant. The project will use the technology of proton and solvent coupled hydrolysis to hydrolyze the organosilane, which is lower environmental impact and commercial availability. The research for the starting point is the oriented self-assembly of the organosilicon molecules formed from organosilane hydrolysis on the wood surfaces, and the research will center on the scientific issues for the formation mechanism of polymer films with low surface energy and micro- and nano-scale rough structure bonded on the wood surfaces, and under the guidance of the theory of amphiphobic wetting and molecular self-assembly, we will investigate the mechanism of amphiphobic wood surface fabricated with controlled hydrolysis-condensation of organosilane using the characterization methods including 29Si NMR, XPS, FTIR-ATR and quantum chemistry calculation. We will study the influence mechanism between molecular self-assembly and the wetting properties of wood surfaces under the condition of varied hydrolysis technology for organosilane. At the same time, the coating thickness, surface morphology and dual scale roughness on the wood surfaces formed from molecular self-assembly of organosilane will be explored with ellipsometer, SEM, and laser scanning confocal microscope (LSCM) profilometry. The heat resistance, anti-aging, acid and alkali resistance, corrosion resistance, and physical and mechanical properties for functionalized wood are also be analyzed. Furthermore, the influence mechanism between the treatment technology and functionalization properties of wood is investigated in detail and we can provide a scientific basis for a novel creating amphiphobic wood surfaces after the completion of the research.

赋予木材表面双疏功能是保护木材免受外界水分和油污影响的关键，是实现木材高效利用的有效手段。本项目筛选环境友好、价格低廉的有机硅烷，采用质子溶剂耦合水解技术，以有机硅分子在木材表面定向沉积自组装为切入点，围绕木材表面键合具有低表面能和微纳粗糙结构的高分子聚合物薄膜的形成机制这一科学问题，在双疏理论及模型、分子自组装理论的指导下，采用29Si NMR、XPS、FTIR-ATR等现代技术和量子化学计算的方法分析有机硅烷水解-缩聚构筑双疏木材的形成机制，研究水解工艺对有机硅烷在木材表面分子自组装及润湿特性的影响机制，分析有机硅烷在木材表面自组装后的成膜厚度、表面形貌和微纳粗糙度，分析功能化对木材的耐热、抗老化、耐酸碱、耐腐蚀及木材物理力学性能的影响机制，探索改性处理工艺与功能化特性之间的影响机制，为木材表面双疏功能化技术体系的创新设计提供科学依据。

赋予木材表面双斥功能或疏水功能是保护木材免受外界水分和油污影响的关键，是实现木材高效利用的有效手段。斥油材料表面通常采用氟化合物来修饰，项目探索含氟化合物的替代品，减小氟化合物对人体健康和生态环境带来的潜在危害，采用无氟化合物制备了防水、油润湿和渗透的功能化刨花板、木材和竹材。.（1）以甲基三甲氧基硅烷（MTMS）为功能化单体，将浓度为0.1mol/L的盐酸与MTMS按照体积比(1:4)混合，在盛有冰浴的超声波中进行不同时间的水解，然后将刨花板、木材、竹材试样放入水解后的溶液中浸渍5 min，取出自然晾干或烘干；所制备的刨花板、木材或竹材兼具斥水和斥油的性能，尤其是具有极强的防油渗透特性，同时还提高了板材的强度。（2）以甲苯为溶剂，以不同链长的烷基三氯硅烷：甲基三氯硅烷（-CH3）、正丁基三氯硅烷（-C4H9）、十二烷基三氯硅烷（-C12H25）和十八烷基三氯硅烷（-C18H37）分别为功能化单体配制不同浓度的溶液，采用液相沉积自组装的方法，在思茅松和西南桦木材表面利用“一步”法制备了接触角大于150°的具有超疏水性的木材，显著降低了木材的吸水率，探讨了链长及浓度对所改性木材的物理及化学性能的影响。（3）将酚醛（PF）树脂胶粘剂的合成和纳米氧化亚铜（Cu2O）的制备在同一反应体系中同时进行，制得了含有不同种类纳米Cu2O颗粒的PF树脂；结合低表面能物质硬脂酸（STA）修饰，采用简单的喷涂和浸渍工艺，在木材表面成功实现了超疏水功能；对超疏水木材的各项性能进行了测试和表征，并对改性机理进行了探讨。