Anomalous Ultrasound Attenuation near the Critical Point of n-Pentanol–Nitromethane Solution Stratification

Abstract

A binary n-pentanol-nitromethane solution in the homogeneous state near the critical stratification point is acoustically studied in a frequency range of 5÷2800 MHz. The experiment confirmed the existence of the anomalous ultrasound attenuation, which can be analyzed in terms of the effective ultrasound absorption. On the basis of experimental data, the regular and fluctuation components of the effective ultrasound absorption coefficient of the solution are resolved. It is shown that the fluctuation part of the effective absorption coefficient can be described in the framework of the Ferrell-Bhattacharjee theory of heat capacity relaxation. On the basis of this theory with the use of the obtained experimental data, the crossover scaling function is determined, and its parameters and Ω 1/2 are found. K e y w o r d s: binary solutions, critical stratification point, ultrasound absorption coefficient, crossover function.

Thermodynamic Parameters of the Viscous Flow in the Aqueous Solutions of Polyols

“…From the magnitude of the segment intercepted by this line on the abscissa axis, the transmission coefficient and the true entropy and free energy [Eqs. (5) and (6)] can be found.…”

“…A large number of works dealt with the study of those properties that are crucial for those industries, in particular, the influence on the progress of various diseases [3,4], changes in the taste of food, and transport parameters [1,2]. Much less attention, in our opinion, is paid to the study of the thermal motion of molecules in such objects and its thermodynamic characteristics [5][6][7][8]. In this work, we report the results of our studies concerning the thermodynamic parameters of a viscous flow, which were obtained on the basis of the data obtained for the shear viscosity coefficients of polyols, their aqueous solutions, and some of their melts.…”

Physical Nature of Relaxation Time in Aqueous Alcoholic Solutions

“…Запропонована картина еволюцiї зародкiв задовiльно узгоджується з експериментальними даними. Використовуючи методи динамiчного розсiяння свiтла [4,5,8], а також ультразвукової спектроскопiї [18,19], встановлено, що радiальнi коливання зародкiв приводять до виникнення пiка поглинання ультразвуку. При цьому, характерна частота положення пiка задовiльно узгоджується з частотами коливань поверхнi зародкiв.…”