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Abstract Gold nanoparticles (AuNPs) were synthesized in microfluidic mixers by means of response surface methodology (RSM). A reverse‐staggered herringbone micromixer was employed and reaction temperature, concentration ratio of reactants, Reynolds number, and pH of chloroauric acid were varied, with desired responses being particle size and peak intensity from UV spectroscopy. RSM was performed by simultaneously optimizing variable ranges to identify the best fit of polynomial equations to experimental data. Results revealed the individual and synergistic roles of each reaction variable on particle size and UV peak intensity, leading to identification of the largest design space. The effect of reaction variables on AuNP synthesis and particle size was confirmed in serpentine mixers.
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Infrared compatible rapid mixer to probe millisecond chemical kinetics
Fast microfluidic mixers are a valuable tool for studying solution-phase chemical reaction kinetics and molecular processes with spectroscopy. However, microfluidic mixers that are compatible with infrared vibrational spectroscopy have seen only limited development due to the poor infrared transparency of the current microfabrication material. We describe the design, fabrication, and characterization of CaF2-based continuous flow turbulent mixers, which are capable of measuring kinetics in the millisecond time window with infrared spectroscopy, when integrated into an infrared microscope. Kinetics measurements demonstrate the ability to resolve relaxation processes with 1 millisecond time resolution, and straightforward improvements are described that should result in sub-100 µs time-resolution.
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- Award ID(s):
- 2011854
- PAR ID:
- 10400079
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- Review of Scientific Instruments
- Volume:
- 94
- Issue:
- 3
- ISSN:
- 0034-6748
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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