Critical behavior of the ultrasonic attenuation and velocity and shear viscosity for the binary mixture of nitrobenzene-<i>n</i>-hexane

Abstract

Ultrasonic velocity and absorption as a function of temperature, concentration, and frequency (5–25 MHz) and shear viscosity as a function of concentration and temperature are reported for the binary mixture nitrobenzene-n-hexane in the homogeneous phase above Tc. For the observed absorption at critical concentration and critical temperature αc/f2 vs f−1.06 yields a straight line as predicted by the dynamic scaling theory of Ferrell and Bhattacharjee [Phys. Rev. A 24, 1643 (1981)]. Also, the critical amplitudes of the thermal expansion and specific heat have been calculated using the two-scale factor universality relation. The adiabatic coupling constant g is calculated and compared to the experimental value. In addition, the experimental values of α/αc (where α is the absorption at critical concentration above the critical temperature) for nitrobenzene-n-hexane are compared to the scaling function F(ω*) and show a good agreement with the theory. Finally, the velocity for the system at the critical concentration above the critical temperature appears to decrease linearly with increasing temperature.