Nathanael Konstantia, Kovalchuk Nina M, Simmons Mark J H
School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, UK.
Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, Limassol 3036, Cyprus.
Micromachines (Basel). 2025 Jan 10;16(1):75. doi: 10.3390/mi16010075.
This study evaluates the performance of continuous flow and drop-based microfluidic devices for the synthesis of silver nanoparticles (AgNPs) under identical hydrodynamic and chemical conditions. Flows at low values of Dean number (De < 1) were investigated, where the contribution of the vortices forming inside the drop to the additional mixing inside the reactor should be most noticeable. In the drop-based microfluidic device, discrete aqueous drops serving as reactors were generated by flow focusing using silicone oil as the continuous phase. Aqueous solutions of reagents were supplied through two different channels merging just before the drops were formed. In the continuous flow device, the reagents merged at a Tee junction, and the reaction was carried out in the outlet tube. Although continuous flow systems may face challenges such as particle concentration reduction due to deposition on the channel wall or fouling, they are often more practical for research due to their operational simplicity, primarily through the elimination of the need to separate the aqueous nanoparticle dispersion from the oil phase. The results demonstrate that both microfluidic approaches produced AgNPs of similar sizes when the hydrodynamic conditions defined by the values of De and the residence time within the reactor were similar.
本研究评估了连续流和基于液滴的微流控装置在相同流体动力学和化学条件下合成银纳米颗粒（AgNPs）的性能。研究了低Dean数（De < 1）下的流动情况，此时液滴内部形成的涡旋对反应器内额外混合的贡献应该最为显著。在基于液滴的微流控装置中，以硅油作为连续相，通过流动聚焦产生作为反应器的离散水滴。试剂水溶液通过在水滴形成前刚刚合并的两个不同通道供应。在连续流装置中，试剂在三通接头处合并，并在出口管中进行反应。尽管连续流系统可能面临诸如由于颗粒沉积在通道壁上或结垢导致颗粒浓度降低等挑战，但由于其操作简单，主要是通过无需将水性纳米颗粒分散体与油相分离，它们在研究中通常更实用。结果表明，当由De值定义的流体动力学条件和反应器内停留时间相似时，两种微流控方法产生的AgNPs尺寸相似。
