Ammonia Catalyzed Hydrolysis-Condensation Kinetics of Tetraethoxysilane/Dimethyldiethoxysilane Mixtures Studied by 29 Si NMR and SAXS
作者:Yao Xu、Xianyong Sun、Dong Wu、Yuhan Sun、Yongxia Yang、Hanzhen Yuan、Feng Deng、Zhonghua Wu
DOI:10.1007/s10953-006-9117-y
日期:2007.3.30
condensation of the mixed systems of tetraethoxysilane (TEOS) and dimethyldiethoxysilane (DDS) dissolved in methanol. With ammonia catalysis, the hydrolysis reaction orders for TEOS and DDS in the mixed systems remained first order, which is similar to that observed for their corresponding single silane component precursor systems. The hydrolysis rate constant for TEOS in the mixed systems was larger than that
原位 29Si 液态核磁共振 (NMR) 用于研究四乙氧基硅烷 (TEOS) 和二甲基二乙氧基硅烷 (DDS) 溶解在甲醇中的混合体系的氨催化水解和缩合。在氨催化下,混合体系中 TEOS 和 DDS 的水解反应顺序仍为一级,这与在它们相应的单一硅烷组分前体系统中观察到的类似。TEOS 在混合体系中的水解速率常数大于 TEOS 在单一硅烷组分前体体系中的水解速率常数。同时,混合前驱体体系中DDS的水解速率常数小于单一硅烷组分前驱体体系中DDS的水解速率常数。水解和缩合动力学表明 TEOS 和 DDS 之间的水解-缩合相对速率更相容,这显着影响了所得二氧化硅颗粒的最终微观结构。小角 X 射线散射 (SAXS) 实验显示颗粒网络中具有典型的双分形结构。