A Microfabricated Gas–Liquid Segmented Flow Reactor for High-Temperature Synthesis: The Case of CdSe Quantum Dots

✍ Scribed by Brian K. H. Yen; Axel Günther; Martin A. Schmidt; Klavs F. Jensen; Moungi G. Bawendi

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 190 KB
• Volume: 44
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.200500792

✦ Synopsis

Microfluidic reactors enable a number of advantages over conventional chemical processes including enhanced control of heat and mass transfer, lower reagent consumption during optimization, and sensor integration for in-situ reaction monitoring. [1,2] Reactors are usually fabricated from either silicon, glass, or polymers; those made of silicon or glass are advantageous because they can tolerate a broad range of chemistries and high temperatures. Microreactors for the large class of homogeneous liquid-phase reactions are often based on single-phase laminar flow designs in which reagent streams are brought into contact. However, such designs are limited in terms of slow diffusive reagent mixing and broad residence time distributions (RTDs). Recirculation within segments in a two-phase segmented flow approach (gasliquid or liquid-liquid) overcomes such limitations by providing a mechanism of exchanging fluid elements located near the channel walls with those at the center. [3][4][5] This recirculatory motion has the dual effect of narrowing the RTD and improving reactant mixing. In contrast to single-phase designs, segmentation makes it possible to drive reactions to required yields over significantly shorter times owing to the enhanced mixing, while maintaining narrow RTDs.