Use of second-harmonic superimposition to induce chemical effects of ultrasound
Use of second-harmonic superimposition to induce chemical effects of ultrasound
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DOI：
10.1021/jp962137a
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发表时间：
1996-11-28
影响因子：
--
通讯作者：
Umemura, S
中科院分区：
文献类型：
--
作者：
Kawabata, K;Umemura, S
我们研究了二次谐波叠加（SHS）对两个频率分量：10.3和2.06 MHz的超声诱导碘离子氧化的影响。与SHS，氧化率达到最大值时，基本的二次谐波的声强度比约为1：1，而传统的单频暴露在两个频率之一，即使在声强度的10倍的阈值SHS没有诱导氧化。氧化率强烈依赖于第二谐波相对于基波的相位。该反应仅在从最大化峰稀疏度到最大化稀疏度增加速率的二次谐波阶段观察到。同时测量的次谐波发射，空化的一个指标，表明SHS的声化学反应的效果是由于它的能力，有效地诱导空化。
We investigated the effect of second-harmonic superimposition (SHS) on the oxidation of iodide ions induced by ultrasound with two frequency components: 10.3 and 2.06 MHz. With SHS, the oxidation rate reached a maximum when the acoustic intensity ratio of the fundamental to the second harmonic was about 1:1, while conventional single-frequency exposure at either one of the two frequencies did not induce oxidation even at an acoustic intensity 10 times the threshold for SHS. The rate of oxidation strongly depended on the phase of the second harmonic relative to the fundamental. The reaction was observed only at the second-harmonic phase ranging from maximizing the peak rarefaction to maximizing the rarefaction increasing rate. Simultaneously measured subharmonic emission, an indicator of cavitation, suggested that the effect of SHS on sonochemical reaction is due to its ability to induce cavitation efficiently.