摘要
In this paper, an ultrasound with frequency of 815 kHz was used to research the sonochemical yield in a small-size reverberation field by the method of fluorescent spectrum analysis. There are two characteristics on the effect of sonochemistry in the reverberation field: First, the cavitation threshold was about 0.3 W / cm2 (it was 0.7 W / cm2 in travelling field); Second, when the sound intensity was larger than the threshold, the sonochemical yield increased as the intensity increased and increased rapidly after the intensity was at 1.69-2.13 W / cm2, so that there was a upturned point in the curve of the result (which would tend to saturation in the travelling field). The theoretical analysis shows that the reason of the threshold decrease is that the sound energy density becomes high in the reverberation field, and the upturned point results from the disturbance of the radiation pressure on the liquid surface. Therefore, by experiment and theory this paper shows that a reverberation field has to be built for the higher sonochemical yield.
In this paper, an ultrasound with frequency of 815 kHz was used to research the sonochemical yield in a small-size reverberation field by the method of fluorescent spectrum analysis. There are two characteristics on the effect of sonochemistry in the reverberation field: First, the cavitation threshold was about 0.3 W / cm2 (it was 0.7 W / cm2 in travelling field); Second, when the sound intensity was larger than the threshold, the sonochemical yield increased as the intensity increased and increased rapidly after the intensity was at 1.69-2.13 W / cm2, so that there was a upturned point in the curve of the result (which would tend to saturation in the travelling field). The theoretical analysis shows that the reason of the threshold decrease is that the sound energy density becomes high in the reverberation field, and the upturned point results from the disturbance of the radiation pressure on the liquid surface. Therefore, by experiment and theory this paper shows that a reverberation field has to be built for the higher sonochemical yield.
基金
Project is supported by the National Natural Science foundation of China the work has been finished in the labouratory of Modern Acoustics,Nanjing University,Nanjing
