原位液体室透射电镜观察二氧化硅纳米颗粒的合并生长  

Observation of Coalescence Growth of Silica Nanoparticles Using in Situ Liquid Cell Transmission Electron Microscopy

作　　者：杨天旭 徐旭荣[2] 唐睿康[1] YANG Tianxu;XU Xurong;TANG Ruikang(Department of Chemistry,Zhejiang University,Hangzhou 310027,China;Qiushi Academy for Advanced Studies,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学化学系,浙江杭州310027 [2]浙江大学求是高等研究院,浙江杭州310027

出　　处：《材料科学与工程学报》2023年第1期6-12,38,共8页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(21471129)。

摘　　要：利用原位液体室透射电子显微镜实时观察硅酸钠溶液中二氧化硅纳米颗粒的生长过程,同时使用动态光散射对纳米颗粒尺寸分布进行原位监测。通过对该动态过程的定量分析,研究了二氧化硅纳米颗粒的生长机理。结果表明,硅酸钠溶液中二氧化硅纳米颗粒主要是通过合并的方式进行生长。在合并的过程中,颗粒会自发地进行连续合并或发生形状改变,以降低单位体积表面能。进一步的结果分析显示,二氧化硅纳米颗粒的合并生长符合基于Smoluchowski速率方程的动力学,接近于受反应控制的聚集生长,其化学本质是颗粒表面羟基间的脱水缩合反应。In situ liquid cell transmission electron microscopy(LC-TEM)and dynamic light scattering(DLS)were used to observe the growth of silica nanoparticles in real-time.Quantitative analyses of the dynamic processes reveal associated growth mechanisms of silica nanoparticles.It is found that silica nanoparticles in aqueous solution growth mainly by coalescing with each other.During the coalescence process,continual coalescence or shape change of silica nanoparticles occurs spontaneously,in order to reduce surface energy per volume.The coalescence growth kinetics of silica nanoparticles can be described by Smoluchowski’s equation,and are characteristic of reaction-limited aggregation.In essence,the chemical reaction involved in coalescence is dehydration condensation reaction between hydroxyl groups on the surface of silica nanoparticles.Our results would serve as an important reference to understand the growth mechanisms of nanoparticles and realize their controllable syntheses.

关 键 词：二氧化硅纳米颗粒 原位液体室透射电镜 合并生长 动态光散射 羟基 

分 类 号：O648[理学—物理化学]