An acoustic study of the relaxation properties of ZhK-1282 nematic liquid crystals in the vicinity of the nematic-isotropic phase transition

The viscous and elastic properties of a ZhK-1282 nematic liquid crystal (NLC) were studied in a temperature interval from 290 to 360 K by method of ultrasonic spectroscopy in the 3-63 MHz frequency range. The temperature dependences of the NLC density and shear viscosity are presented. The results of measurements of the velocity and attenuation of ultrasound and the shear viscosity were used to calculate the volume viscosity coefficient, the moduli of dilatation and isothermal compressibility, the relaxation times of the elastic and viscous properties, and the corresponding critical characteristics of the given NLC. (C) 2005 Pleiades Publishing, Inc.