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MO: Fachverband Molekülphysik
MO 6: Molecular Spectroscopy of Liquid Jets II
MO 6.1: Talk
Tuesday, March 11, 2025, 11:00–11:15, HS XV
Determination of chemical kinetics from diffusion limited chemical reactions in free-flowing liquid flat-jets — •Hanns Christian Schewe1, Nicolas Velasquez2, Bruno Credidio2, Aaron Ghrist2, Andreas Osterwalder3, Gerard Meijer2, Bernd Winter2, and Christophe Nicolas4 — 1J. Heyrovský Institute of Physical Chemistry, Prague, Czech Republic — 2Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany — 3Institute for Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland — 4Synchrotron SOLEIL, Gif-sur- Yvette Cedex, France
We presents a methodology for conducting chemical kinetics studies at the interface between two (aqueous) solutions. When two streams from two microchannels impinge under laminar flow conditions, a flat-leaf structure forms, thereby creating an inherent liquid-liquid interface between the two solutions flowing along each other. Initially, the chemiluminescence from a luminol oxidation reaction is employed to demonstrate that the fluids do not exhibit turbulent mixing in the first leaf of a flat-jet, thus providing a clean interface between the liquids from the impinging jets [1]. Next, we examine the (de-)protonation dynamics of amine or carboxylic groups, which can be studied using either X-ray absorption spectroscopy to characterize electronic structure changes or Raman microscopy to quantify vibrational changes. We illustrate how kinetic data is obtained wherein diffusion represents the sole transport process responsible for mixing across the liquid-liquid interface. [1] H.C.Schewe et. al. J. Am. Chem. Soc. 2022, 144, 17
Keywords: flat-jet; X-ray spectroscopy; Raman spectroscopy; diffusion limited chemical reaction