High-temperature microfluidic synthesis of CdSe nanocrystals in nanoliter droplets
High-temperature microfluidic synthesis of CdSe nanocrystals in nanoliter droplets
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DOI：
10.1021/ja051381p
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发表时间：
2005-10-12
影响因子：
15
通讯作者：
Mathies, RA
中科院分区：
文献类型：
--
作者：
Chan, EM;Alivisatos, AP;Mathies, RA
提出了在全氟化载体流体中流过微型反应器的纳升体积液滴中高温合成 CdSe 纳米晶体的方法。通道高度逐步增加的流聚焦纳米喷射结构在 Fomblin Y 06/6 全氟化聚醚中可重复生成十八碳烯液滴，毛细管数高达 0.81，液滴与载液粘度比为 0.035。镉和硒前体以十八烯液滴形式流过高温（240-300 摄氏度）玻璃微反应器，产生了高质量的 CdSe 纳米晶体，经光谱学和透射电子显微镜验证。将反应溶液隔离在液滴中可以防止颗粒沉积和流体动力学分散，从而可以在 4 小时内的三种不同温度和四种不同停留时间下重复合成纳米晶体。我们在高温、高毛细管数和低粘度比下合成了各种纳米晶体，说明了基于液滴的微流体反应器在封装纳升体积的有机或水溶液以及精确控制化学或生化反应方面的通用性。
The high-temperature synthesis of CdSe nanocrystals in nanoliter-volume droplets flowing in a perfluorinated carrier fluid through a microfabricated reactor is presented. A flow-focusing nanojet structure with a step increase in channel height reproducibly generated octadecene droplets in Fomblin Y 06/6 perfluorinated polyether at capillary numbers up to 0.81 and with a droplet:carrier fluid viscosity ratio of 0.035. Cadmium and selenium precursors flowing in octadecene droplets through a high-temperature (240-300 degrees C) glass microreactor produced high-quality CdSe nanocrystals, as verified by optical spectroscopy and transmission electron microscopy. Isolating the reaction solution in droplets prevented particle deposition and hydrodynamic dispersion, allowing the reproducible synthesis of nanocrystals at three different temperatures and four different residence times in the span of 4 h. Our synthesis of a wide range of nanocrystals at high temperatures, high capillary numbers, and low viscosity ratio illustrates the general utility of droplet-based microfluidic reactors to encapsulate nanoliter volumes of organic or aqueous solutions and to precisely control chemical or biochemical reactions.