Solutions Mixing Visualization in Continuous-Flow Microreactors via Interferometric Technique

Abstract

The paper demonstrates the potential of interferometry as a visualization technique for studying the mixing processes of liquid reagents in continuous-flow microreactors. We visualized two types of instabilities: double-diffusion convection and Marangoni soluto-capillary convection. We employed two optical schemes, depending on how large values of refractive index inhomogeneities resulting from instabilities needed to be visualized, including the shear interferometer and the Fizeau interferometer. The interferometry enabled a qualitative investigation of the structure and dynamics of the generated convection. In addition, by implementing the phase shift method by the IntelliWave program, we quantified the efficiency of the mixing process between pumped liquids. These quantitative findings complemented our qualitative visualization, providing further evidence of the effectiveness of interferometry in studying mixing processes. Our results confirm that the interferometry technique is an effective tool for the visualization and analysis of convective flows in continuous-flow microreactors. Moreover, the insights gained from this research contribute to the broader understanding and optimization of mixing processes in microreactor systems.