High-Temperature Microfluidic Synthesis of CdSe Nanocrystals inNanoliter Droplets
The high-temperature synthesis of CdSe nanocrystals innanoliter-volume droplets flowing in a perfluorinated carrier fluidthrough a microfabricated reactor is presented. A flow-focusing nanojetstructure with a step increase in channel height reproducibly generatedoctadecene droplets in Fomblin Y 06/6 perfluorinated polyether atcapillary numbers up to 0.81 and with a droplet:carrier fluid viscosityratio of 0.035. Cadmium and selenium precursors flowing in octadecenedroplets through a high-temperature (240-300 degrees C) glassmicroreactor produced high quality CdSe nanocrystals, as verified byoptical spectroscopy and transmission electron microscopy. Isolating thereaction solution in droplets prevented particle deposition andhydrodynamic dispersion, allowing the reproducible synthesis ofnanocrystals at three different temperatures and four different residencetimes in the span of four hours. Our synthesis of a wide range ofnanocrystals at high temperatures, high capillary numbers, and lowviscosity ratio illustrates the general utility of droplet-basedmicrofluidic reactors to encapsulate nanoliter volumes of organic oraqueous solutions and to precisely control chemical or biochemicalreactions.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director. Office of Science. Office of Basic EnergySciences. Materials Sciences and Engineering Division
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 908488
- Report Number(s):
- LBNL-58076; JACSAT; R&D Project: 506101; BnR: KC0203010; TRN: US0703704
- Journal Information:
- Journal of the American Chemical Society, Vol. 127, Issue 40; Related Information: Journal Publication Date: 2005; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
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