Development of Microfluidic Reactor for Continuous Production of Monosized Nanocrystals

这项研究的目的是进行所需的理论研究，以设计用于工业规模合成纳米晶体的微流控反应器，用于纳米晶体的使用点制造，或探索在其形成过程中发生的过程。许多单独的微反应器，包括它们的试剂导入系统和流动通道，可以包含在一个绝缘体上的硅晶片中，从而实现并行化，并在合成和制造中实现前所未有的控制和可扩展性。方法是使用两种不相容的液体，其通道几何形状可以诱导分散在另一相中的一相液滴的自发生成。然后，这些液滴将通过反应堆，并严格控制停留时间。反应堆内的各个区域将被加热，以促进化学反应，从而导致半导体纳米晶体的成核。然后，原子核将流向其他更冷的区域，在那里不会发生进一步的成核，但现有的原子核可以增长，以达到所需的粒子特征。第一阶段的工作将是对芯片设计、微流控现象以及纳米晶体的形成和演化进行集成建模。二是对稳定的两相流进行建模，优化微反应器流道结构。第三项研究将使用模型硒化镉系统完成纳米晶体合成的热化学和动力学描述，并创建一个“虚拟”反应堆。这项研究解决了将“纳米卷积”的好处推广到普通公众的最严重的障碍之一，即我们目前无法大量生产符合商业应用现实的纳米晶体。如果没有这块制造的关键踏脚石，大量的基础研究将被浪费，这些研究已经确定了纳米晶体的无数应用。这项研究还将通过工程学院的卓越课程，为历史上代表性不足的工程学本科生提供研究经验。

The objective of this research is to conduct the theoretical studies needed to design a microfluidic reactor for synthesizing nanocrystals on an industrial scale, for point-of-use manufacture of nanocrystals, or to probe the processes occurring during their formation. Numerous individual microreactors, including their reagent introduction systems and flow channels, could be contained in a single silicon-on-insulator wafer, allowing parallelization, and unprecedented control and scalability in synthesis and manufacturing. The approach is to employ two immiscible liquids, with a channel geometry that induces spontaneous generation of droplets of one phase dispersed in the other. These droplets will then pass through the reactor with a tightly controlled residence time. Individual zones within the reactor will be heated to promote chemical reactions leading to the nucleation of semiconducting nanocrystals. The nuclei will then flow to other, cooler zones where no further nucleation could occur, but existing nuclei could grow to achieve desired particle characteristics. The first phase of work will be integrated modeling of the chip design, microfluidic phenomena, and nanocrystal formation and evolution. The second will model the stable two-phase flow, and optimize the microreactor flow channel configuration. The third will complete the thermochemical and kinetic description of nanocrystal synthesis, using the model cadmium selenide system, and create a "virtual" reactor.The research addresses one of the most serious barriers to extending the benefits of the "nanorevolution" to the general public, namely our current inability to manufacture nanocrystals in quantities that are realistic for commercial applications. Without this crucial stepping-stone to manufacturing, the vast amount of fundamental research that has identified innumerable applications of nanocrystals would be wasted. The research will also offer research experiences to historically under-represented engineering undergraduates through the College of Engineering's SUPERB program.