Shear Thickening and Time-Dependent Rheological Behavior in Aqueous Polyacrylic Ester Dispersions
✍ Scribed by J. Xu; A.M. Jamieson; S.Q. Wang; S. Qutubuddin
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 154 KB
- Volume
- 182
- Category
- Article
- ISSN
- 0021-9797
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✦ Synopsis
and light diffraction (6). Dynamic simulations have repro-We have observed, in a commercial aqueous polyacrylic ester duced many of the essential features of the shear thickening dispersion, a shear thickening phenomenon that exhibits timerheology (7-10). In sterically-or electrostatically-stabilized dependent rheological behavior. The critical shear rate g g c for the dispersions of uniform spherical particles, shear flow proshear thickening transition varies with volume fraction, temperaduces an ordered two-dimensional layered structure. At sufture, pH, and particle size distribution, in a manner which indificiently high shear rates, hydrodynamic forces overcome cates that the phenomenon is associated with a reversible shearthe interparticle repulsion forces so that the ordered state is induced colloidal order-disorder transition. However, we find broken up, resulting in a disordered state with an apparent that, in the shear thickening region, the rheology may also evolve geometrical jamming leading to a sudden rise in viscosity.
with time. Our observations suggest that the time-dependence is caused by the temporary formation of particle clusters at high The disordered state may involve the transitory formation shear rates.