A high throughput co-flow millifluidic device for homogeneous nanoparticle synthesis

Abstract

Nanoparticle (NP) and its encapsulation have received increasing attention due to their potential applications in various industrial sectors. However, conventional batch NP synthesis processes have shortcomings including limited batch-to-batch reproductivity, and nonhomogeneous particle chemical and physical properties. In this work, a novel polydimethylsiloxane (PDMS) based co-flow millifluidic (CFM) device was developed to achieve a rapid and precise control of the mixing of two fluids through vortices and turbulence for nanoparticle synthesis and encapsulation. The flow behavior phase diagram was obtained by operating the CFM device under different flow rates of the fluids that generated different flow types such as laminar jet flow, confined laminar flow, transition, turbulent jet flow and micro-vortices and turbulence flows. In addition, a computational study was conducted to understand the flow characteristics in these flow regimes. At last, polystyrene (PS) NPs and perylene-encapsulated polystyrene nanoparticles (P-ENP) were synthesized using the CFM device. The comparison of the size distribution of PS NPs with those from bulk synthesis shows that the CFM device can synthesize NPs and ENPs with much smaller sizes and more uniform size distributions. The developed CFM device shows great potential as a powerful platform for high throughput production of NPs and ENPs.