Ultrasonic Propagation in Binary Liquid Systems near Their Critical Solution Temperature

An investigation has been made on the propagation of ultrasonic waves (at 600 kc) through the critical solution temperature of two binary liquid systems; (1) aniline and n-hexane and (2) triethylamine and water. Results are given for the variation of the velocity with temperature. The behavior of the sound attenuation through the critical point is also shown. In both systems studied the attenuation exhibited a marked maximum at the critical solution temperature. A possible explanation of this effect is that the sound wave gives rise to configurational relaxation processes of greatly increased magnitude on account of the molecular clustering in the liquid system near its critical solution temperature.