Effects of Sample Volume and Frequency on Ultrasonic Power in Solutions on Sonication

Effects of the sample volume and frequency on the decomposition of 5,10,15,20-tetrakis(4-sulfonatophenyl) porphyrin (H2TPPS4-) were studied at frequencies of 126 and 500 kHz and 1 MHz. The decomposition of the porphyrin depended on the cell radius and liquid height. The decomposition ratio, (1-R TPPS), was expressed by the fractional power law of the sample volume V, where R TPPS is defined as the ratio for the absorption of the porphyrin in solution before and after ultrasonic irradiation. The effect of frequency on the decomposition of the porphyrin was estimated from the slope of the plot of (1-R TPPS) versus V for different frequencies. The decomposition rate decreased with increasing the irradiated frequency.