Abstract

Capturing Fast Organometallic Transformations in Microfluidics Devices

Marc Garland, Principal Scientist II, Institute of Chemical and Engineering Sciences (ICES)

Fast chemical transformations are often difficult to capture in a spectroscopic manner. Under typically steady state flow conditions, a 1 micrometer spatial resolution in the axial direction of a channel in a microfluidics device translates to circa a 1 millisecond temporal resolution. Accordingly, Raman microscopic mapping measures (circa 40 x 40 pixels) were performed in the channels of a microfluidics device, followed by extensive signal processing using the Band-Target Entropy Minimization (BTEM) algorithm. In the first case, 2 non-reactive flows are contacted in a device under laminar flow in order to demonstrate some of the main concepts. In the second case, a fast organometallic reaction is studied where the lifetime of the intermediate is less than 1 second.  The pure component spectrum of the intermediate is reconstructed using BTEM and this spectrum is compared to DFT spectral prediction. Further signal processing provides a 2D map of the reaction zone, and the presence of the intermediate at the interface is confirmed. The present results illustrate the usefulness of combining spectroscopy, microfluidics, DFT and signal processing in order to better understand flow chemistry.