High-Throughput Synthesis of Uniform Mg(OH)2 Nanoparticles in an Oscillating Feedback Minireactor Designed by the Selective Dimension Scale-Out Method

Based on a selective dimension scale-out method, a high-throughput oscillating feedback minireactor (OFM) was developed to prepare uniform Mg(OH)2 nanoparticles using a precipitation method. Three-dimensional unsteady simulations indicated that three secondary flows (i.e., vortex, feedback, and oscillation) could effectively induce chaotic advection, and OFM could improve mixing performance compared to those using the microreactor before amplification. The Villermaux–Dushman experiments showed that high-efficiency micromixing could be achieved within 3.9 ms. The average size of the Mg(OH)2 nanoparticles decreased with the increase of total flow rate (Qtotal), as well as with the decrease of precursor concentration and C(Mg2+)/C(OH–) ratio. Mg(OH)2 with an average particle size of 53.0 nm and narrow particle size distribution (PSD) was obtained at a high throughput of 180 mL/min. Compared with the products obtained in the initial microreactor, the product quality was maintained or even improved, suggesting that the scale-out method is reliable and effective.