Abstract
The complex shear viscosity of sterically stabilized colloidal dispersions of different-sized silica particles (radius a=28–76 nm) was measured with torsion resonators and a nickel-tube resonator between 80 Hz and 200 kHz. The volume fraction of the samples was varied from 0.10 to 0.60. In the intermediate-frequency region, the real and the imaginary parts of the complex shear viscosity decay as to their limiting values. The viscoelastic behavior can be described in terms of one relaxation strength and a series of relaxation times with = . The complex shear viscosity scales with the dimensionless relaxation strength /, the dimensionless relaxation time /, and the dimensionless angular frequency ω/. The dimensionless groups / and / are a function of the volume fraction only. At higher volume fractions the high-frequency limiting values of the real part of the complex shear viscosity, , corroborate values calculated by Beenakker [Physica 128A, 48 (1984)].
- Received 6 July 1988
DOI:https://doi.org/10.1103/PhysRevA.39.795
©1989 American Physical Society