Elucidation of fast chemical reactions such as protein folding requires resolution on a submillisecond time scale. However, most quench-flow and stop-flow techniques only allow chemical processes to be studied after a few milliseconds have elapsed. In order to shorten the minimum observation time for quench-flow experiments, we designed a miniaturized mixer assembly. Two “T” mixers connected by a channel are etched into a 1 cm × 1 cm silicon chip which is interfaced with a commercially available quench-flow instrument. Decreasing the volume of the mixing chambers and the distance between them results in an instrument with greatly reduced dead times. As a test of submillisecond measurements, we studied the basic hydrolysis of phenyl chloroacetate. This reaction proceeds with a second-order rate constant, k = 430 M-1 s-1, and shows pseudo-first-order kinetics at high hydroxide concentrations. The chemical reaction data demonstrate that the silicon device is capable of initiating and quenching chemical reactions in time intervals as short as 110 μs. The performance of these mixers was further confirmed by visualization using acid−base indicators.
SUMMARYWe present here, a micromachined, high Reynolds number (2,000 -6,000), sub-millisecond liquid mixer for the study of chemical reaction kinetics. This 1cm x 1cm x 1mm bulk micromachined silicon mixer is capable of initiating and quenching (starting and stopping) chemical reactions in intervals as short as 100 µs. The centimeter sized mixer chip contains two tee mixers connected by one channel which serves as a reaction chamber. Each tee mixer consists of opposing channels where liquids meet head-on and exit into a third channel forming the base of a "T." Our mixer performance was characterized by employing two carefully chosen chemical reactions with reaction time constants of 3 ms and 9 ms along with visualization techniques using dyes and acid-base indicators.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.