Ultrasonic Interferometer on Shear Waves in Liquids

Russian Physics Journal - The developed ultrasonic interferometer on low-frequency shear waves in liquids is described. The problem of the piezo-quartz crystal – liquid interlayer –...     

Impedance method for measuring shear elasticity of liquids

Experimental results of studying low-frequency (74 kHz) shear elasticity of polymer liquids by the impedance method (analogous to the Mason method) are presented. A free-volume thick liquid layer is placed on the horizontal surface of a piezoelectric quartz crystal with dimensions 34.7 × 12 × 5.5 cm. The latter performs tangential vibrations at resonance frequency. The liquid layer experiences shear strain, and shear waves should propagate in it. From the theory of the method, it follows that, with an increase in the layer thickness, both real and imaginary resonance frequency shifts should exhibit damped oscillations and tend to limiting values. For the liquids under study, the imaginary frequency shift far exceeds the real one, which testifies to the presence of bulk shear elasticity.     

Shear elasticity and strength of the liquid structure by an example of diethylene glycol

Experimental data for the dependence of the low-frequency (10⁵ Hz) shear elasticity of diethylene glycol on the shear deformation angle have been presented. At small shear angles, the range of linear elasticity has been observed, which narrows with rising strain. The effective viscosity behaves similarly.     

Low-frequency shear elasticity of liquids

The shear modulus and mechanical loss tangent are measured for several liquids in the frequency region between 10⁴ and 10⁵ Hz. It is found that an increase in frequency is accompanied by a decrease in the shear modulus and an increase in the mechanical loss tangent.     

Low-Frequency Shear Elasticity of a Colloid Nanosuspension

Acoustical Physics - The paper presents the experimental results of an acoustic impedance study of low-frequency (105 Hz) shear elasticity of a colloidal SiO2 suspension of differently sized...     

Shear elasticity of fluids at low-frequent shear influence

The visco-elastic properties of liquids have been investigated using acoustical resonance method. Piezoquatrz performed tangential oscillations on the main resonance frequency of 74 kHz contacts by the one end of horizontal surface with the studied liquid layer covered by quartz cover-plate. So the stagnant shear waves are installed in layer. The solution of interaction of piezoquartz-liquid layer-cover-plate gives three methods of determination of the real shear modulus (G) and the tangent of mechanical loss angle (tan theta) of liquid. The first method is realized at smaller thickness of liquid layer then the length of shear wave. Liquids of different classes have been studied using this method: polymer liquids, oils, glycols and alcohols. The second method is connected with the propagation of shear wave in liquid layer, parameters of which are determined the G and tan theta. And the third method is based on the determination of limit shift of resonance frequencies at completes damping of shear wave in thick layer of liquid. All these three methods give satisfactory agreement of results.