Accession Number : AD0629179
Title : SHEAR WAVE PROPAGATION IN BIREFRINGENT VISCOELASTIC LIQUIDS OF LOW RIGIDITY AND LOW VISCOSITY.
Descriptive Note : Technical rept.,
Corporate Author : OKLAHOMA STATE UNIV STILLWATER RESEARCH FOUNDATION
Personal Author(s) : Thurston,G. B.
Report Date : MAR 1966
Pagination or Media Count : 34
Abstract : Utilizing the optical birefringence induced by shearing deformation of viscoelastic liquids it is possible to carry out direct quantitative measurements of the progression of a shear wave in the liquid. From measurements of the amplitude and phase of the optical effect versus propagation distance, values of the attenuation and phase constants of the medium are obtained. From these, a complex coefficient of viscosity is determined. An improved optical detection scheme permits measurements as near to the shear wave source as 100 microns with a field resolution of approximately 10 microns. It is thus possible to carry out measurements for liquids of viscosity near that of water and having very low rigidity. A theoretical model for a dilute suspension of rigid macromolecules of ellipsoidal shape is described and measured values are compared with the theory. This is done for an aqueous suspension of colloidal alumina, Dupont 'Baymal', with good general agreement as to frequency and temperature dependence of the propagation characteristics. Measured values are also presented for a polyethylene oxide polymer in combination with Baymal in water. (Author)
Descriptors : (*MECHANICAL WAVES, PROPAGATION), (*SHEAR STRESSES, LIQUIDS), VISCOELASTICITY, ALUMINUM COMPOUNDS, OXIDES, WATER, POLYETHYLENE PLASTICS, OPTICAL ANALYSIS
Subject Categories : Physical Chemistry
Distribution Statement : APPROVED FOR PUBLIC RELEASE