Experimental and numerical insights into the formation of zirconia nanoparticles: a population balance model for the nonaqueous synthesis
Experimental and numerical insights into the formation of zirconia nanoparticles: a population balance model for the nonaqueous synthesis
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DOI：
10.1039/c7re00005g
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发表时间：
2017-06
影响因子：
3.9
通讯作者：
P. Stolzenburg;G. Garnweitner
中科院分区：
文献类型：
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作者：
P. Stolzenburg;G. Garnweitner
研究了氧化锆纳米颗粒的非水合成，以阐明工艺参数和最终纳米颗粒特性之间复杂的相互作用。我们确定了化学反应动力学，并推导了反应常数的模型方程，以描述合成过程作为温度和前体浓度的函数。在研究成核动力学时，我们能够通过小角度 X 射线散射表明，颗粒以 2 nm 的尺寸范围以圆形形状成核。目前对四方相变到单斜相变的理解通过一种新模型得到了扩展，该模型将颗粒经历相变的概率与颗粒尺寸联系起来。导出的模型函数产生了一个全面的群体平衡方程框架，可以模拟整个颗粒形成过程，以预测最终纳米颗粒的特性及其在合成过程中的演变。在模拟结果的支持下，我们解释了为什么单斜颗粒在最终产品中的尺寸比四方颗粒小，这乍一看似乎与热力学相冲突。
The nonaqueous synthesis of zirconia nanoparticles was investigated to elucidate the complex interplay between process parameters and final nanoparticle properties. We determined the chemical reaction kinetics and derived a model equation for the reaction constant to describe the course of the synthesis as a function of temperature and precursor concentration. While investigating the nucleation kinetics, we were able to show via small-angle X-ray scattering that particles nucleate in roundish shapes in a size regime of 2 nm. The current understanding of the tetragonal-to-monoclinic phase transformation was extended by a novel model that relates the probability of particles undergoing the phase transition to the particle size. The derived model functions result in a comprehensive population balance equation framework that can simulate the entire particle formation process to predict final nanoparticle properties as well as their evolvement during the synthesis. Supported by the simulation results, we unravel why monoclinic particles are present in the final product in smaller sizes than tetragonal particles which at first seems to be in conflict with thermodynamics.