CAJ | 학술논문

采用聚二甲基硅氧烷材料（PDMS）制备矩形截面的微通道，并在微通道壁面上沉积 MnO2作为催化剂，采用高速摄影仪对通流过程中过氧化氢催化分解生成氧气气泡的过程进行了可视化实验研究，分析了反应物的浓度和流量对气泡生长速度及脱离直径的影响。结果表明：气泡在微通道内催化表面的生长及脱离过程呈周期性变化的趋势；气泡生长可以分为快速生长和缓慢生长两个阶段，当t＜3 s时气泡处于快速生长阶段，催化反应主要受动力学控制，当t≥3 s时扩散控制占主要地位，气泡生长速度随反应物浓度的升高而增大；气泡脱离直径受反应物浓度影响较小，受反应物流量影响较大，而且随液相反应物Reynolds数的增大线性降低。
채용취이갑기규양완재료（PDMS）제비구형절면적미통도，병재미통도벽면상침적 MnO2작위최화제，채용고속섭영의대통류과정중과양화경최화분해생성양기기포적과정진행료가시화실험연구，분석료반응물적농도화류량대기포생장속도급탈리직경적영향。결과표명：기포재미통도내최화표면적생장급탈리과정정주기성변화적추세；기포생장가이분위쾌속생장화완만생장량개계단，당t＜3 s시기포처우쾌속생장계단，최화반응주요수동역학공제，당t≥3 s시확산공제점주요지위，기포생장속도수반응물농도적승고이증대；기포탈리직경수반응물농도영향교소，수반응물류량영향교대，이차수액상반응물Reynolds수적증대선성강저。
A rectangular microchannel was fabricated with polydimethylsiloxane (PDMS) material and MnO2 catalysts were deposited on the wall of the microchannel. The growth and detachment process of oxygen bubbles generated by the catalytic reaction of H2O2 solution were recorded by a high speed camera. The effects of reactant concentration and flow rate on bubble growth rate and detachment diameter were also analyzed. The growth and detachment process of bubbles generated on the catalytic surface in the microchannel occurred periodically. Moreover, the bubble growth consisted of two processes, the initial fast growth process and the later slow growth process. Before 3 s, the generated bubbles were in a fast growth period, and reaction kinetics dominated the process. However, after 3s, reaction rate was controlled by diffusion, resulting in the fact that bubble growth rate increased with increasing reactant concentration. In addition, bubble detachment diameter was slightly affected by reactant concentration, while it was significantly affected by reactant flow rate and dropped linearly as Reynolds number increased.