Preparation and Control of the Size Distribution of Zirconia Nanoparticles in a Concentric‐Axle Dual‐Pipe Microreactor

Abstract

A dual-pipe-type microreactor was applied to the formation of nanoparticles at a very rapid reaction rate. As a representative example, zirconia particles were produced by supplying zirconium tetrabutoxide solutes and alcohol/water mixtures. The effects of the solvent and alcohol types and the residence time on the particle properties were examined. Zirconia particles were produced and grown in an inner fluid, and no precipitation of particles was observed at the wall in the outer fluid. When ethanol was used as a solvent for diluting water, the zirconia particles had a sharp narrow size distribution that could not be attained by means of a conventional batch method. The mean particle size was successfully controlled in the range of 4-600 nm merely by changing the mean residence time and the concentrations of zirconium tetrabutoxide and water in the presence of a dispersant, polyethyleneimine.

Synthesis of silver nanoparticles in a microfluidic coaxial flow reactor

“…[21][22][23] One type of design that alleviates the occurrence of fouling is the coaxial ow reactor (CFR) which allows an inner stream of reagent to be surrounded by an outer stream, creating a reaction interface between the streams. 15,16,[24][25][26][27][28] The CFR is less susceptible to fouling because the reduction of precursor ions and nucleation of metal NPs occur at the interface between the inner and outer streams, rather than near the channel walls. This reduction in fouling relies on the ow prole of the channel remaining in a stable laminar regime.…”

“…The mass transfer of the reagents in the microdevice determined the size and monodispersity of the NPs which was demonstrated by using different solvent types, tube diameters and precursor concentrations. Maki et al employed a concentric-axle dual-pipe microreactor to synthesise zirconia NPs, 25 and showed that increasing residence time resulted in larger NPs. Abou Hassan et al used a coaxial ow device operated under laminar ow conditions to synthesise iron oxide, goethite and Fe 2 O 3 @SiO 2 core/shell NPs.…”

Mild Microfluidic Approaches to Oxide Nanoparticles Synthesis

“…The rotation speed and laser power were optimized to minimize the content of copper(II) oxide NPs, yielding Cu 2 O NPs of 14 � 1 nm. Upon standing in air at 50 °C, 2013 RT spherical 100-600 [b] 0.2-0.3 [12] Cu 2 O Cu vortex fluidic device 2019 RT 14 [c] 0.07 [c] [69] CuO for pulsed laser ablation 11 [c] 0.09 [c] [a] Calculated by TEM/SEM analysis. [b] Size range obtained by modulating residence times and reagents concentration in the absence of surfactant.…”

Numerical study of a packed-bed microreactor based on Sierpinski fractal principle

“…Microreactor can operate in a continuous flow mode, which brings additional advantages for improving process efficiency [7,8] and ability to perform multi-step syntheses by consecutively coupling reactors with various enzymes [9]. Continuous flow microreactor has a wide range of research fields, including catalysis [10][11][12], nanoparticle synthesis [13], sensors [14], electrochemistry [15] and polymerization [16]. In addition, the laminar flow mode can be obtained in microreactor to achieve good process control [17].…”