The growth of silica nanoparticles by agglomeration and viscous flow sintering is studied from free molecular to transition regime by off‐lattice event‐driven (ED) simulations. Coagulation by simultaneous agglomeration and sintering takes place at high temperature environments, where sintering and collision rates are comparable. The effect of temperature on aggregate mobility and gyration radii, particle morphology, and collisional enhancement is elucidated. The ratio between the characteristic sintering time and characteristic collision time controls the particle size and structure, quantified by the mass fractal dimension. The aggregate morphology depends solely on the ratio of characteristic times and is insensitive to the process temperature. When sintering is negligible, the overall collision frequency is 90% larger than that predicted by the classic Fuchs collision kernel for monodisperse agglomerates, in agreement with experiments. The ED‐obtained quasi‐self‐preserving size distributions are consistent with mobility size distributions measured in hot‐wall reactors and flame sprays.

中文翻译：

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团聚和烧结形成的分形颗粒的结构和动力学

通过离网事件驱动（ED）模拟研究了通过团聚和粘性流烧结从游离分子到过渡态的二氧化硅纳米粒子的生长。在烧结和碰撞率相当的高温环境下，通过同时附聚和烧结进行混凝。阐明了温度对聚集体迁移率和回转半径，颗粒形态以及碰撞增强的影响。特征烧结时间和特征碰撞时间之间的比值控制着颗粒的大小和结构，由质量分形维数来量化。聚集体形态仅取决于特征时间的比率，并且对过程温度不敏感。如果烧结可以忽略不计，与实验一致，整体碰撞频率比经典Fuchs碰撞核对单分散团聚物的预测频率高90％。ED获得的准自保持粒度分布与在热壁反应堆和火焰喷雾器中测得的迁移率粒度分布一致。