Abstract
The behavior of colloidal gels under pressure-driven flow in square microchannels is quantified by microscopic particle image velocimetry (μPTV) and compared to predictions of available rheological models. The gels consist of hydrophobically modified silica microspheres (Φ = 0.15-0.33) suspended in a refractive index-matched fluid along with fluorescent tracers to aid visualization. Measured velocity flow profiles show a transition from plug flow to more fluid-like behavior with increasing volumetric flow rate (Q) at all Φ. This transition is not captured by theoretical predictions of the flow profile based on the Herschel-Bulkley model. Rather, a model that accounts for gel breakup into a suspension of clusters at elevated shear rates by assuming a finite viscosity at infinite shear is needed to accurately predict the flow behavior of colloidal gels at large Q.
Original language | English (US) |
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Pages (from-to) | 8726-8731 |
Number of pages | 6 |
Journal | Langmuir |
Volume | 23 |
Issue number | 17 |
DOIs | |
State | Published - Aug 14 2007 |
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Surfaces and Interfaces
- Spectroscopy
- Electrochemistry