Sebastian Victor
Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain.
Department of Chemical Engineering and Environmental Technologies, University de Zaragoza, 50018, Zaragoza, Spain.
Nanoscale. 2022 Mar 24;14(12):4411-4447. doi: 10.1039/d1nr06342a.
Over the last decade, a multitude of synthesis strategies has been reported for the production of high-quality nanoparticles. Wet-chemical methods are generally the most efficient synthesis procedures since high control of crystallinity and physicochemical properties can be achieved. However, a number of challenges remain from inadequate reaction control during the nanocrystallization process; specifically variability, selectivity, scalability and safety. These shortcomings complicate the synthesis, make it difficult to obtain a uniform product with desired properties, and present serious limitations for scaling the production of colloidal nanocrystals from academic studies to industrial applications. Continuous flow reactors based on microfluidic principles offer potential solutions and advantages. The reproducibility of reaction conditions in microfluidics and therefore product quality have proved to exceed those obtained by batch processing. Considering that in nanoparticles' production not only is it crucial to control the particle size distribution, but also the shape and chemical composition, this review presents an overview of the current state-of-the-art in synthesis of anisotropic and faceted nanostructures by using microfluidics techniques. The review surveys the available tools that enable shape and chemical control, including secondary growth methods, active segmented flow, and photoinduced shape conversion. In addition, emphasis is placed on the available approaches developed to tune the structure and chemical composition of nanomaterials in order to produce complex heterostructures in a continuous and reproducible fashion.
在过去十年中，已报道了多种用于制备高质量纳米颗粒的合成策略。湿化学方法通常是最有效的合成程序，因为可以实现对结晶度和物理化学性质的高度控制。然而，在纳米结晶过程中，由于反应控制不足，仍存在一些挑战；具体而言，包括可变性、选择性、可扩展性和安全性。这些缺点使合成过程变得复杂，难以获得具有所需性能的均匀产品，并且在将胶体纳米晶体的生产从学术研究扩大到工业应用方面存在严重限制。基于微流体原理的连续流动反应器提供了潜在的解决方案和优势。微流体中反应条件的可重复性以及由此产生的产品质量已被证明超过了间歇处理所获得的结果。考虑到在纳米颗粒的生产中，不仅控制粒径分布至关重要，而且控制形状和化学成分也很关键，本文综述了利用微流体技术合成各向异性和多面纳米结构的当前技术水平。该综述调查了能够实现形状和化学控制的现有工具，包括二次生长方法、主动分段流动和光诱导形状转换。此外，重点介绍了为调整纳米材料的结构和化学成分而开发的现有方法，以便以连续和可重复的方式生产复杂的异质结构。
