Precise Measurement of Ultrasonic Absorption in Micellar Solutions in the Frequency Range from 0.2 to 10 MHz

Publisher Website
Google Scholar
Abstract
A cylindrical resonator for the measurement of ultrasonic absorption has been designed. It was found that a newly designed resonator can determine the absolute value of the ultrasonic absorption coefficient of water at frequencies above 0.7 MHz. For aqueous solutions it has a sufficient resolution power down to 0.2 MHz by means of a reference measurement. Precise measurements of ultrasonic absorption were carried out for aqueous solutions of dodecyltrimethylammonium bromide using a newly designed resonator and two other previously reported resonators. The ultrasonic relaxation spectra show a single relaxation process within the investigated frequency range. The relaxation process can be ascribed to a “fast” relaxation related to the exchange of a surfactant between micelles and bulk solution. The kinetic parameters for the exchange process were estimated on the basis of Teubner’s theory.