Determination of temperatures within acoustically generated bubbles in aqueous solutions at different ultrasound frequencies
Determination of temperatures within acoustically generated bubbles in aqueous solutions at different ultrasound frequencies
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DOI：
10.1021/jp061441t
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发表时间：
2006-07-13
影响因子：
3.3
通讯作者：
Grieser, Franz
中科院分区：
文献类型：
--
作者：
Ciawi, Envi;Rae, James;Grieser, Franz
使用甲基自由基重组 (MRR) 方法在叔丁醇水溶液 (0-0.5 M) 中以三个超声波频率（20、355 和 1056 kHz）测量平均声泡温度。该方法基于对甲基自由基重组形成的一些烃产物的产率测量，这些甲基自由基是在含有叔丁醇蒸气的破裂气泡内热产生的。发现平均气泡温度在 355 kHz 和 1056 kHz 下随着叔丁醇浓度的增加而大幅降低，但在 20 kHz 下仅小幅降低。将在 20°C 的本体溶液温度下测得的平均温度外推至叔丁醇浓度为零，得出的顺序为 355 kHz (4300 +/- 200 K) > 1056 kHz (3700 +/- 200 K) > 20 kHz (3400 +/- 200 K)。还得出结论，从 MRR 方法得出的温度是用于感测活动声泡内的热状况的有用诊断参数。然而，必须注意的是，MRR 方法得出的温度在理论上并没有明确的定义。
Mean acoustic bubble temperatures have been measured using a methyl radical recombination (MRR) method, at three ultrasound frequencies (20, 355, and 1056 kHz) in aqueous tert-butyl alcohol solutions (0-0.5 M). The method is based on yield measurements of some of the hydrocarbon products formed from the recombination of methyl radicals that are thermally generated within collapsing bubbles containing tert-butyl alcohol vapor. The mean bubble temperatures were found to decrease substantially with increasing tert-butyl alcohol concentration at 355 and 1056 kHz but only to a small extent at 20 kHz. Extrapolating the mean temperatures measured to zero concentration of tert-butyl alcohol, at a bulk solution temperature of 20 C, gave the order 355 kHz (4300 +/- 200 K) > 1056 kHz (3700 +/- 200 K) > 20 kHz (3400 +/- 200 K). It is also concluded that the temperature derived from the MRR method is a useful diagnostic parameter for sensing the thermal conditions within an active acoustic bubble. However, attention must be given to the fact that the temperature derived from the MRR method is not theoretically well defined.