Controlling fine particle formation processes using a concentric microreactor

Abstract

in Wiley InterScience (www.interscience.wiley.com).To clarify the mechanism of fine-particle formation processes in a multilamination type microreactor that proceeds mainly due to molecular-diffusion-induced mixing, the relation between the size and distribution, and reaction-operation condition in experimental and numerical approaches is investigated. For experimental study, a concentric microreactor was used, and titania fine-particle formation was examined as a model reaction. Based on the hypothesis on the fine-particle formation mechanism, from the experimental results derived, a relatively simple calculation model was made, and validity demonstrated by showing the coincidence of the calculation results and the experimental results. Also, the calculation model was used to establish a technique for predicting the reactant concentration profiles in the microchannel, particle-growth rate, number of formed particles, and nucleation region. Thus, the proposed analysis method will be useful as a guideline for designing microreactors to form fine particles, and will

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

“…The ZTB concentration was set to 0.05 M. The particle size decreased with an increase in the H 2 O concentration of reactant B. Similar results were obtained in the case of titania particle formation [14]. When the H 2 O concentration was less than 20 wt %, the degree of supersaturation in the nucleation process was reduced due to a lack of H 2 O supply, and a small number of nuclei were formed.…”

“…Fig. 2 illustrates a proposed mechanism for the nucleation and the growth of particles in the microreactor in our previous work [14]. Both processes occur at the interface of the two fluids.…”

“…tion. The CV reflects the length of nucleation time [14], and the supersaturation degree was smaller at lower H 2 O concentration. This result demonstrates that the lower H 2 O concentration was suitable to obtain fine particles with narrow distribution.…”

“…Monomodal particles from 5 to 150 nm were successfully controlled by regulating the residence time at the sub-second level and other reaction conditions. Additionally, it was proven that this microreactor was effective at estimating the nucleation region, which is an important factor in particle formation, particle-formation frequency distribution in the region, and behavior of the particlegrowing process [13][14][15].…”

Mikrofluidik in der anorganischen Chemie

“…Sie können durch unterschiedliche Prozesse hergestellt werden, von denen einige problemlos auf die Mikrofluidiktechnologie zu übertragen sind. [44,[94][95][96][97][98][99][100][101] Durch [98] Die Teilchen erhielt man über den so genannten Stöber-Prozess. […”