Influence of microbubbles on free radical generation by ultrasound in aqueous solution: implication of the important roles of nanobubbles
Influence of microbubbles on free radical generation by ultrasound in aqueous solution: implication of the important roles of nanobubbles
复制标题
DOI：
10.1007/s11164-021-04612-6
复制
发表时间：
2021-10
影响因子：
3.3
通讯作者：
K. Tsuchida;Akane Maruyama;Yuma Kobayashi;Gen Sato;R. Atsumi;Y. Murakami
中科院分区：
文献类型：
--
作者：
K. Tsuchida;Akane Maruyama;Yuma Kobayashi;Gen Sato;R. Atsumi;Y. Murakami
虽然微泡的研究已经引起了许多研究者的兴趣，但关于微泡对自由基形成的影响以及对有机化合物在超声辐射下的降解速率的研究还很少。本文首次报道了超声辐射在MBS溶液中对酸性橙7的降解作用。结果表明，只有在45 kHz超声辐照微泡溶液时，酸性橙7的降解速度才会加快。用KI法测量了MBS中气体对声化学效率的依赖关系，发现MBS中气体对声化学效率的依赖顺序为Kr >； Ar ~ N_2>； O_2>； He，支持了所观察到的现象是由于45 kHz超声辐照产生的空化现象。用不同的商业超声振荡器研究了超声频率和功率的依赖关系，并利用带有两个超声发生器的流动反应器系统进一步研究了微泡的尺寸分布对声化学效率的影响。最后，我们证明了超声频率比微泡的大小对45 kHz超声辐照MBS溶液的声化学增强更敏感，并讨论了纳米气泡在目前观察到的现象中的可能作用。
Although research on microbubbles (MBs) has intrigued a lot of researchers, very few studies have been done about the influences of MBs on the free radical formation and also on the degradation rates of organic compounds by ultrasonic irradiation. Here we report the degradation of Acid Orange 7 by the ultrasound irradiation in the solution of MBs for the first time. It was found that acceleration of the degradation rate of Acid Orange 7 was observed only for the 45 kHz ultrasonic irradiation to the microbubble solution. Dependence of gases inside the MBs on the sonochemical efficiencies with the existence of MBs was also measured using the KI method and it was found that the dependence of the sonochemical efficiencies on gases inside the MBs was in the order of Kr > Ar ~ N2> O2> He, supporting the conclusions that the observed phenomena were due to the cavitation by the 45 kHz ultrasonic irradiation. The dependences of ultrasonic frequency and power were investigated using various commercially available ultrasonic oscillators, and the influence of the size distribution of microbubbles on the sonochemical efficiencies was further investigated using a flow reactor system with two ultrasound generators. Finally, we showed that the frequency of the ultrasound was more sensitive than the size of microbubbles for the sonochemical enhancement by the 45 kHz ultrasonic irradiation to the solution of MBs and then discussed possible roles of nanobubbles in the presently observed phenomena.