119. Design and Validation of an Additively Manufactured Flow Cell–Static Mixer Combination for Inline NMR Spectroscopy

Martin Bornemann, Simon Kern, Nico Jurtz, Tobias Thiede, Matthias Kraume, and Michael Maiwald, Industrial & Engineering Chemistry Research, (2019) DOI: 10.1021/acs.iecr.9b03746

There have been an increasing number of publications on flow chemistry applications of compact NMR. Despite this, there is so far no comprehensive workflow for the technical design of flow cells. Here, we present an approach that is suitable for the design of an NMR flow cell with an integrated static mixing unit. This design moves the mixing of reactants to the active NMR detection region within the NMR instrument, presenting a feature that analyses chemical reactions faster (5–120 s region) than other common setups. During the design phase, the targeted mixing homogeneity of the components was evaluated for different types of mixing units based on CFD simulation. Subsequently, the flow cell was additively manufactured from ceramic material and metal tubing. Within the targeted working mass flow range, excellent mixing properties as well as narrow line widths were confirmed in validation experiments, comparable to common glass tubes.