Ultrasonic Absorption in Triethylamine–Water Solution near Its Critical Solution Temperature

Abstract

Ultrasonic absorption (3, 5, and 10 MHz) and velocity (5 MHz) in triethylamine–water binary liquid system have been investigated through the critical solution temperature by means of the pulse‐echo method. The results are obtained for the variation of velocity with temperature and also for the behavior of the attenuation near the critical point. For each frequency investigated, the absorption exhibits a marked maximum at the critical solution temperature. The temperature dependence of the attuenation ${\mathrm{\alpha \hspace{0.17em}/\hspace{0.17em}\nu }}^2$ in the single phase of the solution is examined in terms of the Fixman theory. The result is in reasonable agreement with the theory with regard to functional conformity of ${\mathrm{\alpha \hspace{0.17em}/\hspace{0.17em}\nu }}^2$ in temperature and frequency. The temperature dependence of the velocity at 5 MHz is quite similar to the results obtained for 600 kHz, and no dispersion is observed.