The critical conditions for secondary nucleation of silica colloids in a batch Stober growth process
The critical conditions for secondary nucleation of silica colloids in a batch Stober growth process
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DOI：
10.1016/j.ceramint.2007.07.009
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发表时间：
2008-09
影响因子：
5.2
通讯作者：
K. Chou;Chen-Chih Chen-Chen-Chih-Chen-92175041
中科院分区：
文献类型：
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作者：
K. Chou;Chen-Chih Chen-Chen-Chih-Chen-92175041
在这项工作中，我们通过实验确定了溶液中二氧化硅种子的临界总表面积，以避免在批量Stöber生长过程中形成新颗粒（即二次成核）。该临界表面积对应于来自TEOS水解的反应中间体的产生速率与其通过现有晶种的生长的消耗速率之间的平衡。进一步的计算表明，二次成核可能与晶种颗粒间的平均距离有关。当晶种之间的距离对于每种生长条件（即对于每种生成速率）超过临界值时，将观察到二次成核。除此之外，观察到简单生长。较高的产生速率对应于较短的距离。
In this work, we determined experimentally the critical total surface area of silica seeds in the solution to avoid the formation of new particles (i.e. secondary nucleation) in a batch Stöber growth process. This critical surface area corresponded to the balance between the generation rate of reaction intermediate from the hydrolysis of TEOS and its consumption rate via the growth of existing seeds. Further calculation showed that the secondary nucleation was probably related to the average distance between seed particles. When the distance between seeds exceeded a critical value for each growth condition, i.e. for each generation rate, one would then observe secondary nucleation. Otherwise, simple growth was observed. Higher generation rate corresponded to shorter distance.