Generation of metal nanoparticles in a microchannel reactor
Generation of metal nanoparticles in a microchannel reactor
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DOI：
10.1016/j.cej.2003.11.021
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发表时间：
2004-08
影响因子：
15.1
通讯作者：
J. Wagner;T. Kirner;G. Mayer;J. Albert;J. Köhler
中科院分区：
文献类型：
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作者：
J. Wagner;T. Kirner;G. Mayer;J. Albert;J. Köhler
通过柠檬酸盐还原生成的 12 纳米金纳米颗粒在基于芯片的相互扩散微反应器中进行处理，在 μl/min 范围内的流速下没有明显吸附到表面。此外，还测试了微反应器胶体金纳米颗粒的生成和生长。采用晶种生长方法，从 12 nm 柠檬酸盐稳定的金晶种开始，制备直径范围为 15 至 24 nm 的较大颗粒。该方法使用抗坏血酸作为还原剂，而 12nm 种子作为成核中心。为了稳定颗粒，使用聚乙烯吡咯烷酮。通过分析离心方法或原子力显微镜测定粒度分布。记录胶体溶液的紫外-可见光谱。产生的颗粒的尺寸分布通过反应物的流速、它们的浓度比以及反应物添加的顺序而改变。在进行的实验中，平均粒径随着流速的降低而增加，并且只有当晶种浓度等于或低于 Au3+ 的浓度时才观察到颗粒生长。如果不添加聚乙烯吡咯烷酮，所产生的胶体溶液不稳定并在7天内分解。
Twelve nanometer Au nanoparticles generated by citrate reduction were handled in a chip-based interdiffusion microreactor without significant adsorption to the surfaces at flow rates in the μl/min-range. Furthermore, the microreactor was tested for the generation and growth of colloidal gold nanoparticles. Following a seeding growth approach, starting from 12nm citrate-stabilised gold seeds, larger particles of diameters ranging from 15 to 24nm were prepared. This method makes use of ascorbic acid as reducing agent, while the 12nm seeds serve as nucleation centers. For particle stabilization polyvinyl pyrrolidone was employed. Particle size distributions were determined by an analytical centrifugation method or atomic force microscopy. UV-Vis spectra of the colloidal solutions were recorded. The size distribution of the produced particles is altered by the flow rate of the reactants, their concentration ratio as well as the order of the reactant addition. In the conducted experiments the mean particle diameter increases with decreasing flow rate and particle growth was only observed, if the concentration of seeds was equal or lower than the concentration of Au3+. Without the addition of polyvinyl pyrrolidone, the produced colloidal solutions were unstable and decomposed within 7 days.