(536f) Jet-Mixing Microreactor for Metal and Metal-Oxide Nanomaterial Synthesis and Scale-up Considerations

The market for nanomaterials is expected to double in the next three years, calling for the creation of innovative technologies that can produce bulk material while maintaining the quality obtained at lab scale. The properties of nanomaterials are highly dependent on the mixing dynamics of their synthesis process. Macromixing in conventional batch nanomaterial syntheses increases the overall mixing time, leading to a variability within batches and a wide particle size distribution. These problems can be circumvented by using microreactors that provide a small mixing time because of their associated micromixing and mesomixing. We have developed a simple, inexpensive continuous jet-mixing reactor that is successfully used for silver nanoparticle (Ag NP) synthesis. Ag NPs are synthesized by the common route of silver nitrate reduction with sodium borohydride, using trisodium citrate as the capping agent. It is shown that jet mixing results in a narrow particle size distribution as compared to batch. We also find that the capping agent concentration required for stable Ag NP synthesis using jet-mixing is a factor of four lower than that using batch. Ag NPs synthesized using jet-mixing have greater consistency in optical properties and a longer shelf life when monitored over one month. With the aim of scaling up future nanomaterial syntheses, fundamental studies are underway to characterize the mixing of this reactor.