Sonoluminescence from Aqueous Alcohol and Surfactant Solutions

作者：Muthupandian Ashokkumar, Robert A. Hall, Paul A. Mulvaney, Franz Grieser · 发表于：The Journal of Physical Chemistry B · 年份：1997 · DOI：10.1021/jp972477b · 被引用次数：201 · 研究领域：Ultrasound and Cavitation Phenomena、Ultrasound and Hyperthermia Applications、Photoacoustic and Ultrasonic Imaging

The sonoluminescence generated in water with pulsed 515 kHz ultrasound has been studied in the presence of different chain length (C 1 −C 5 ) aliphatic alcohols and the surfactants sodium dodecyl sulfate (SDS), dodecyltrimethylammonium chloride (DTAC), and N -dodecyl- N, N -dimethyl-3-ammonio-1-propanesulfonate (DAPS). The ultrasound pulse widths used ranged from 1 to 10 ms, with duty cycles (on/off ratios) of 1:3 to 1:9. It was found that the sonoluminescence from the initial pulses was very low but increased in intensity and reached a maximum after 20−50 pulses, for all systems studied, depending on the pulse width and duty cycle. In the presence of alcohol the maximum signal decreased with increasing alcohol concentration, and the signal decline was more pronounced with increasing chain length of the alcohol. A good correlation was found to exist between the decline in the sonoluminescence signal and the Gibbs surface excess of the alcohol at the air/water interface. In the presence of SDS (an anionic surfactant) and DTAC (a cationic surfactant), quite different behavior was observed. At low concentrations of these two surfactants the maximum signal was significantly enhanced over that obtained in pure water, reaching a maximum at about 1 mM of surfactant. At higher concentrations the signal decreased again reaching a limiting value similar to that obtained in pure water. The sonoluminescence signal in DAPS (a zwitterionic surfactant) solutions remained much the same as in...