2004/01/01 by Ilya Shestopalov, Joshua D. Tice, Rustem F. Ismagilov · 2 citations
Engineering · #Innovative Microfluidic and Catalytic Techniques Innovation #Microfluidic and Capillary Electrophoresis Applications #Electrowetting and Microfluidic Technologies
paper · doi:10.1039/b403378g
openalex publication_date 2004/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
This paper reports a plug-based, microfluidic method for performing multi-step chemical reactions with millisecond time-control. It builds upon a previously reported method where aqueous reagents were injected into a flow of immiscible fluid (fluorocarbons)(H. Song et al., Angew. Chem. Int. Ed., 2003, 42, 768). The aqueous reagents formed plugs--droplets surrounded and transported by the immiscible fluid. Winding channels rapidly mixed the reagents in droplets. This paper shows that further stages of the reaction could be initiated by flowing additional reagent streams directly into the droplets of initial reaction mixture. The conditions necessary for an aqueous stream to merge with aqueous droplets were characterized. The Capillary number could be used to predict the behavior of the two-phase flow at the merging junction. By transporting solid reaction products in droplets, the products were kept from aggregating on the walls of the microchannels. To demonstrate the utility of this microfluidic method it was used to synthesize colloidal CdS and CdS/CdSe core-shell nanoparticles.