Droplet-based microfluidic method for robust preparation of gold nanoparticles in axisymmetric flow focusing device
Droplet-based microfluidic method for robust preparation of gold nanoparticles in axisymmetric flow focusing device
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DOI：
10.1016/j.ces.2018.10.010
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发表时间：
2019-02-23
影响因子：
4.7
通讯作者：
Benyahia, Brahim
中科院分区：
文献类型：
--
作者：
Bandulasena, Monalie, V;Vladisavljevic, Goran T.;Benyahia, Brahim
开发了一种新的微流控混合策略，并用于制备聚乙烯吡咯烷酮（PVP）封端的金纳米粒子（AuNPs）。在该方法中，将含有1%（w/v）PVP的1 mM四氯金酸（HAuCl 4）流通过内毛细管注入，并与通过外同轴毛细管并流递送的20 mM L-抗坏血酸溶液混合。通过从外部毛细管的相对侧递送的环境友好油Miglyol 840使反应混合物流体动力学流动聚焦，这导致在锥形收集管中产生反应液滴。反应物通过由液滴内的流体与载体油的流体动力学相互作用引起的内部循环流在液滴内快速混合。所制备的金纳米颗粒的尺寸通过动态光散射和透射电子显微镜测量，并发现随着液滴尺寸的减小和两个反应物流之间的速度差的增加而减小，这提高了液滴内的混合效率。当注射管的出口部分位于收集管的入口部分时，由于液体界面处的最高剪切，获得最小的纳米颗粒。载体油在液滴和反应器壁之间形成疏水屏障，防止合成颗粒的沉积。结果，AuNP的尺寸小于用两个连续反应物流操作的并流混合器中的尺寸。(C)2018爱思唯尔有限公司版权所有
A novel microfluidic mixing strategy was developed and used to prepare polyvinylpyrrolidone (PVP) capped gold nanoparticles (AuNPs). In this process, 1 mM tetrachloroauric acid (HAuCl4) stream containing 1% (w/v) PVP was injected through the inner capillary tube and mixed with 20 mM L-ascorbic acid solution delivered co-currently through the outer coaxial capillary. The reaction mixture was hydrodynamically flow focused by the environmentally friendly oil Miglyol 840 delivered from the opposite side of the outer capillary, which resulted in the generation of reaction droplets in a tapered collection tube. The reactants were rapidly mixed within droplets by internal circulating flows induced by hydrodynamic interactions of fluids inside the droplets with the carrier oil. The size of the prepared AuNPs was measured by both dynamic light scattering and transmission electron microscopy and was found to decrease with decreasing the droplet size and increasing the difference in velocity between the two reactant streams, which improved mixing efficiency within droplets. The smallest nanoparticles were obtained when the outlet section of the injection tube was positioned at the entry section of the collection tube due to the highest shear at the liquid interface. The carrier oil formed a hydrophobic barrier between the droplets and the reactor walls preventing deposition of the synthesised particles. As a result, the size of the AuNPs was smaller than in the co-flow mixer operated with two continuous reactant streams. (C) 2018 Elsevier Ltd. All rights reserved.