A plasma/liquid microreactor for radical reaction chemistry: An experimental and numerical investigation by EPR spin trapping

Abstract

In this paper, a novel plasma/liquid microreactor has been developed to generate and inject radical species with the aim to perform chemical synthesis reactions in liquid phase. Plasma has always been considered as a source of reactive species, such as radicals, atoms, electrons, etc., with applications mostly dedicated to surface modifications of materials. By injecting reactive species created by the plasma to the liquid phase, it is possible to initiate liquid phase synthesis reactions. In addition, gas/liquid interactions can be enhanced with a high surface‐area‐to‐volume ratio by confining the plasma and the liquid in diphasic micro‐structured systems. Herein is reported a novel plasma/liquid microreactor for liquid phase radical reactions. Radicals are generated in the gas phase in a steady flow microreactor and then transported to the liquid phase. The spin trapping reaction and the electron paramagnetic resonance (EPR) spectroscopy have been used to identify and quantify the radical species generated in the microreactor. Hydroxyl radicals and hydrogen atoms have been detected and measured in the liquid phase, indicating the huge potential of the microreactor as a handful tool for chemical synthesis.