Tailoring the size of silver nanoparticles by controlling mixing in microreactors
Tailoring the size of silver nanoparticles by controlling mixing in microreactors
复制标题
通过控制微反应器中的混合来定制银纳米颗粒的尺寸
DOI：
10.1016/j.cej.2021.134112
复制
发表时间：
2022
影响因子：
15.1
通讯作者：
Gao Y
中科院分区：
文献类型：
--
作者：
Gao Y
微反应器通常因其小直径而具有较高的传质速率。尽管这是事实，特别是与间歇系统相比，但单相流微反应器中的混合通常完全由扩散主导，反应物的快速混合是其设计过程中经常被忽视的一个方面。本文首次定量分析了前体混合对流动微反应器中合成的金属纳米粒子的尺寸和分布的影响。通过控制合理设计的微反应器中的混合效率，可以连续合成各种尺寸的银纳米颗粒。由于成核速率的增加以及由此产生的核浓度的增加，颗粒尺寸随着混合指数的增加而减小。在此，通过精确模拟其浓度分布来定量评估不同3D弯曲微反应器的混合效率，使用基于向后粒子跟踪的新颖方法避免所谓的数值扩散误差。改进了基于前向粒子跟踪的方法，以降低计算成本来模拟微反应器中的停留时间分布 (RTD)。众所周知，弯曲反应器通道会导致迪恩涡流的形成，然而，这些明确的旋转会导致停滞区。通过沿着通道长度周期性地改变迪恩涡流的方向，可以提高混合效率并缩小RTD。此外，我们还证明了入口流的配置相对于反应器曲率以及迪恩涡流对最终混合的影响。这些结果为微反应器的设计提供了合理的设计指南，以操纵平流作为操纵反应速率的一种方式，如此处所示以控制纳米颗粒尺寸。
Microreactors are commonly regarded by their high mass transfer rates associated to their small diameters. Although this is true, especially when compared to batch systems, mixing is frequently exclusively dominated by diffusion in single phase flow microreactors, being the fast mixing of reactants an aspect often overlooked during their design. This paper presents the first quantitative analysis of the effect of mixing of precursors on the size and distribution of metal nanoparticles synthesized in flow microreactors. Silver nanoparticles with a range of sizes are continuously synthesized by controlling mixing efficiency in rationally-designed microreactors. The particle size decreases as the mixing index increases due to an increase in nucleation rate and thus the resulting nuclei concentration. Herein, the mixing efficiencies of different 3D curved microreactors are quantitatively evaluated using accurate simulations of their concentration profiles, avoiding the so-called numerical diffusion errors using a novel method based on backward particle tracking. A method based on forward particle tracking is improved to simulate the residence time distributions (RTD) in microreactors at a reduced computational cost.Curving the reactors channels is known to lead to the formation of Dean vortices however, these well-defined rotations lead to stagnant zones. The mixing efficiency can be enhanced and the RTD narrowed by periodically changing the direction of the Dean vortices along the length of the channel. In addition, we demonstrate the effect of the configuration of the inlet streams relative to the curvature of the reactor and thus, the Dean vortices, on the resulting mixing. These results provide rational design guidelines for the design of microreactors to manipulate advection as a way of manipulating the reaction rates as demonstrated here to control nanoparticle sizes.
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影响因子：
15.1
作者：
Kirandeep K. Gill;R. Gibson;K. H. Yiu;P. Hester;N. Reis
通讯作者：
Kirandeep K. Gill;R. Gibson;K. H. Yiu;P. Hester;N. Reis
DOI：
--
发表时间：
1970
期刊：
影响因子：
--
作者：
O. Levenspiel;J. Turner
通讯作者：
J. Turner
扭转的分解演示：光致变色泰勒-库埃特装置
影响因子：
0.9
作者：
E. Fonda;K. Sreenivasan
通讯作者：
K. Sreenivasan
381. 根据隔膜池测量得到的硝酸银水溶液在 25°、35° 和 45° 时的扩散系数
DOI：
--
发表时间：
1962
期刊：
影响因子：
--
作者：
J. Firth;H. Tyrrell
通讯作者：
H. Tyrrell
影响因子：
3.9
作者：
Epps, Robert W.;Volk, Amanda A.;Abolhasani, Milad
通讯作者：
Abolhasani, Milad