Mixing Performance and Application of a Three-Dimensional Serpentine Microchannel Reactor with a Periodic Vortex-Inducing Structure

3D printed microfluidic mixer for real-time monitoring of organic reactions by direct infusion mass spectrometry

3D printing is a technology that has revolutionized traditional rapid prototyping methods due to its ability to build microscale structures with customized geometries in a simple, fast, and low-cost way. In this sense, this article describes the development of a microfluidic mixing device to monitor chemical reactions by mass spectrometry (MS). Microfluidic mixers were designed containing 3D serpentine and Y-shaped microchannels, both with a pointed end for facilitating the spray formation. The devices were fabricated entirely by 3D printing with fusion deposition modeling (FDM) technology. As proof-of-concept, micromixers were evaluated through monitoring the Katritzky reaction by injecting simultaneously 2,4,6-triphenylpropyllium (TPP) and amino acid (glycine or alanine) solutions, each through a different reactor inlet. Reaction product was monitored online by MS at different flow rates. Mass spectra showed that the relative abundances of the products obtained with the device containing the 3D serpentine channel were three times greater than those obtained with the Y-channel device due to the turbulence generated by the barriers created inside microchannels. In addition, when compared to the conventional electrospray ionization mass spectrometry (ESI-MS) technique, the 3D serpentine mixer offered better performance measured in relation to the relative abundance values for the reaction products. These results as well as the instrumental simplicity indicate that 3D printed microfluidic mixer is a promising tool for monitoring organic reactions via MS.

A SAR Micromixer for Water-Water Mixing: Design, Optimization, and Analysis

A numerical investigation of the mixing performance and fluid flow in a new split and recombine (SAR) Y−Uβ micromixer is presented in this work. A parameter called connecting angle βis varied from 0° to 90° to analyze the effect on the SAR process and mixing performance. Thenumerical data shows that the SAR process strongly depends on the connecting angle (β) and maximum efficiency (93%) can be achieved when the value of β is 45°. The Y−U45° the mixer also offers higher efficiency and lower pressure drop than a known SAR ‘H−C’ mixer irrespective of Reynolds numbers. The split and recombine process, the influence of secondary flow, and pressure drop characteristics at various Reynolds numbers are also studied. In addition, mixing effectiveness is also computed, and among all examined mixers, Y−U45° is by far the best performing one.