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Vladimir N. Matveenko, Eugine A. Kirsanov
Viscosity of concentrated dispersions of spherical
particles in the framework of a structural model
Abstract
Abstract.Viscosity curves obtained for four types
of colloidal dispersion of spherical particles with different degrees of
dispersion and composition of the dispersion medium are considered within the
framework of a structural rheological model. The analysis of rheological curves
using three types of coordinate axes is presented. The approximation of the
structural rheological model by rheological equations is carried out at
separate intervals of shear rates. It is shown that in the region of high shear
rates, experimental data are successfully described by a generalized flow
equation (aggregates are destroyed under the action of tensile hydrodynamic
forces). At low shear rates, a rheological equation should be used that takes
into account the additional formation of particle aggregates due to converging
hydrodynamic forces. The magnitude of the coefficients (parameters) of the
rheological equations for the considered colloidal dispersions corresponds to
the conclusions of the structural rheological model, indicating the general
mechanism of the flow of these dispersions.
Key words: structural rheological model, colloidal systems, suspensions,
non-Newtonian system, viscous properties
Copyright (C) Chemistry Dept., Moscow State University, 2002
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