Controllability and Flexibility in Particle Manufacturing of a Segmented Microfluidic Device with Passive Picoinjection

摘要

Segmented flow microfluidics has attracted considerable attention owing to the excellent controllability of reaction environment. However, the accurate and stepwise addition of other reactants into the formed droplets/slugs in segmented flow is extraordinarily challenging to achieve, especially for performing particle growth and crystallization processes. Herein, we employed a segmented flow microchannel with passive picoinjection to realize the accurate addition of reactants and continuous particle manufacturing. A Venturi junction was integrated into the microchannel to control the injection volume without external power. Rapid mixing for the preparation of BaSO4 nanoparticles with an average size of 30-40 nm, multiple injection for the growth of Au nanoparticles from 32 to 91 nm, and continuous crystallization of vaterite CaCO3 with a high crystal purity were all successfully performed in this microchannel. The feasibility of long-term operation and large-scale production of particles by combining with droplet splitting was also experimentally verified. (C) 2018 American Institute of Chemical Engineers