School of Chemistry, University of Melbourne, VIC 3010, Australia.
Chemphyschem. 2010 Jun 7;11(8):1680-4. doi: 10.1002/cphc.200901037.
Images of sonoluminescence, sonophotoluminescence and sonochemiluminescence are recorded in order to semi-quantitatively compare the spatial distribution of the cavitation activity at three different ultrasound frequencies (170 kHz, 440 kHz and 700 kHz) and at various acoustic amplitudes. At all ultrasound frequencies investigated, the sonochemically active cavitation zones are much larger than the cavitation zones where sonoluminescence is observed. Also, the sonochemically active bubbles are observed at relatively lower acoustic amplitudes than that required for sonoluminescence bubbles to appear. The acoustic power required for the observation of the initial cavitation bubbles increases with an increase in the ultrasound frequency. The cavitation bubbles are observed relatively uniformly throughout the reactor at 170 kHz whereas they are located away from the transducer at the higher frequencies used in this study. While these observations highlight the complexities involved in acoustic cavitation, possible reasons for the observed results are discussed.
为了半定量比较在三种不同超声频率（170 kHz、440 kHz 和 700 kHz）和不同声幅下的空化活性的空间分布，记录了声致发光、声致光致发光和声致化学发光的图像。在所研究的所有超声频率下，声致化学活性空化区远大于观察到的声致发光空化区。此外，声致化学活性气泡出现在相对较低的声幅下，低于出现声致发光气泡所需的声幅。观察初始空化气泡所需的声功率随着超声频率的增加而增加。在 170 kHz 时，空化气泡在整个反应器中观察到相对均匀，而在本研究中使用的较高频率下，它们位于换能器之外。虽然这些观察结果突出了声空化所涉及的复杂性，但讨论了观察结果的可能原因。
