Performance of a helical insert in a commercial tubing as a passive micromixer to produce nanoparticles using an emulsification approach

Abstract

Chemical reactions with very fast kinetics, such as nanomaterial production, depend on mixing conditions to control reactant conversion and product selectivity. Mixing at the molecular level (micromixing) is an important stage in the operation of chemical engineering and process technology, with a strong influence on the selectivity, yield, and quality of final products. Micromixers have demonstrated excellent mixing capabilities in many physical and chemical methods. In this study, a new type of passive micromixer based on a helical insert was microfabricated. Interestingly, the micromixer is easy to be assembled into conventional tubings widely used in microfluidics and has no moving parts. The proposed microsystem is robust, compact, and has a modular design that enables the proper combination of mixing units for the on-demand tuning of mixing requirements. Finally, the helical insert could be easily regenerated in the case of fouling. The mixing efficiency of the proposed insert was validated using an acetal cleavage method and was finally successfully tested in the production of single emulsions to form polymeric nanoparticles of high interest in biomedicine. The mixing efficiency of the proposed micromixers is as good as the ones currently used and also offers a plethora of advantages that are not feasible in current systems.