Schmidt Bryan, Mahmud Goher, Soh Siowling, Kim Sun Hee, Page Taylor, O'Halloran Thomas V, Grzybowski Bartosz A, Hoffman Brian M
Department of Chemistry, Northwestern University, Evanston, IL 60208.
Appl Magn Reson. 2011 Feb 11;40(4):415-425. doi: 10.1007/s00723-011-0195-7.
Rapid freeze-quench (RFQ) trapping of short-lived reaction intermediates for spectroscopic study plays an important role in the characterization of biological reactions. Recently there has been considerable effort to achieve submillisecond reaction deadtimes. We present here a new, robust, high-velocity microfluidic mixer that enables such rapid freeze-quenching. It is a based on the mixing method of two impinging jets commonly used in reaction injection molding (RIM) of plastics. This method achieves efficient mixing by inducing chaotic flow at relatively low Reynolds numbers (Re =140). We present the first mathematical simulation and microscopic visualization of mixing in such RFQ micromixers, the results of which show that the impinging solutions efficiently mix within the mixing chamber. These tests, along with a practical demonstration in a RFQ setup that involves copper wheels, show this new mixer can in practice provide reaction deadtimes as low as 100 microseconds.
快速冷冻淬灭（RFQ）捕获短寿命反应中间体用于光谱研究，在生物反应表征中发挥着重要作用。最近，人们为实现亚毫秒级的反应停滞时间付出了巨大努力。我们在此展示一种新型、坚固且高速的微流体混合器，它能够实现如此快速的冷冻淬灭。它基于塑料反应注射成型（RIM）中常用的两种冲击射流混合方法。该方法通过在相对较低的雷诺数（Re = 140）下诱导混沌流来实现高效混合。我们展示了此类RFQ微混合器中混合过程的首次数学模拟和微观可视化，结果表明冲击溶液在混合室内有效混合。这些测试以及在涉及铜轮的RFQ装置中的实际演示表明，这种新型混合器在实际应用中能够提供低至100微秒的反应停滞时间。
