Automation of a low-cost device for flow synthesis of iron oxide nanoparticles

Iron oxide nanoparticles have been of great interest due to their physical and chemical properties, and the coprecipitation method is among the main ways to produce them. Despite being the cheapest and most straightforward method, its main disadvantage during the scale-up process is the increase in the nanoparticle’s polydispersity and the reactor’s dimensions. This way, looking for an alternative to increasing the production scale in the synthesis of Fe₃O₄ by coprecipitation, we developed and optimized a low-cost flow reactor based on peristaltic pumps made of inexpensive DC motors and an Arduino microcontroller. A 2^4–1 experimental design was performed to optimize the Fe₃O₄ coprecipitation parameters such as reagent concentration, flow rate, and reactor size. The flow reactor parameters were verified to affect the size, homogeneity, and stability of Fe₃O₄ nanoparticles with sizes ranging from 5 to 10 nm and polydispersity index varying between 0.15 and 0.45 Furthermore, the product was synthesized in a matter of minutes with rates up to 150 mL min⁻¹ in a low-cost reactor.