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Rapid mixing is a critical step in many nanoparticle syntheses that can impact the ability to scale production from bench to industrial levels. This study combines experimental and computational approaches to characterize mixing dynamics in crossflow jet mixing reactors (JMRs) with millimeter-scale internal dimensions. The Villermaux-Dushman reaction system is used to quantify experimental mixing times across different reactor sizes and flow rates. Complementary computational fluid dynamics (CFD) simulations assess changes in the state of the flow and estimate mixing times under varying operating conditions. Mixing times derived from CFD results agree well with the experimental results for mixing indices between 0.95 and 0.98. To demonstrate the impact of mixing on nanoparticle formation, we synthesize polybutylacrylate-b-polyacrylic acid (PBA-PAA) block co-polymer nanoparticles, confirming the existence of a critical flow rate beyond which particle size stabilizes. Additionally, we produce polylactic acid-co-glycolic acid (PLGA) nanoparticles incorporating a hydrophobic dye, achieving an average particle size below 300 nm at a throughput of ∼ 1.3 kg/day. These results provide insights into optimizing JMRs for high-throughput, reproducible nanoparticle synthesis, bridging the gap between benchtop and industrial-scale production. 

Biomass is a renewable carbon feedstock that can be converted to 5-hydroxymethylfurfural (HMF), a useful platform chemical that can be modified to produce valuable chemicals and fuels. Previous research has shown that high HMF selectivity can be achieved in organic solvents such as dimethyl sulfoxide (DMSO) because of its capability to stabilize HMF in solution, but DMSO is an undesirable solvent to use industrially as product separation from the reaction solution is difficult. Surface functionalization of porous catalysts has been shown as a method to introduce solvent-effects at the surface of heterogeneous catalysts, thus avoiding the need for high boiling solvents like DMSO. Poly(ethylene sulfoxide) (PESO) is added to the surface of sulfonic acid (SA) functionalized SBA-15 silica to obtain the bifunctional catalyst SA-PESO-SBA-15. Co-localization of the sulfoxide polymer with sulfonic acid groups inside the catalyst pores (SA-PESO-SBA-15) increased HMF selectivity to 51% from 26% obtained by monofunctional SA-SBA-15 at 27% fructose conversion in water. Additionally, this bifunctional catalyst performs best in 4 : 1 (w/w) THF : water cosolvent, a more industrially preferred cosolvent system, obtaining 79% HMF selectivity at 87% fructose conversion. Overall, these materials are promising for the selective conversion of fructose to HMF. 

Commonly used batch reactors for nanomaterial synthesis can be difficult to scale since rapid particle nucleation and growth require efficient mixing to produce monodisperse particle size distributions (PSD). Monodisperse particles can be synthesized through efficiently mixing the reactants in the liquid phase using a jet-mixing reactor. Using common synthesis precursors and concentrations, the jet-mixing reactor produces silver nanoparticles with a diameter of 5 ± 2 nm, as characterized by TEM, and a monomodal surface plasmon resonance (SPR) in the UV-vis spectrum. In comparison, a batch synthesis using the same concentrations of reactants produces nanoparticles with a diameter of 9 ± 4 nm and a bimodal SPR, indicating that jet-mixing produces a more monodisperse particle size distribution than batch synthesis. For the jet-mixing synthesis, the concentration of the capping agent can be reduced to a value of 0.05 mM while retaining a narrow full-width of half-maximum (FWHM) of the SPR spectrum. Interestingly, decreasing the capping agent quantity from the standard concentration of 0.2 mM to 0.05 mM decreases the FWHM of the SPR, corresponding to a more monodisperse PSD at lower capping agent concentration. This result is attributed to the increased stabilization at lower ion concentrations in the solution. For low capping agent concentrations, additional experiments adding small amounts of sodium nitrate support this observation. Overall, the jet-mixing reactor represents a viable system for the continuous production of size-controlled silver nanoparticles with reduced amounts of capping agent.