Exploration of the volume fraction above which suspensions of spherical and weakly anisotropic colloid particles cannot flow
- Univ. of Illinois at Urbana-Champaign, IL (United States); Air Force Research Lab., Wright-Patterson Air Force Base, OH (United States); University of Illinois
- Univ. of Illinois at Urbana-Champaign, IL (United States)
In article II of this series, we describe experiments with dense suspensions of spherical and dumbbell shaped colloid particles (particle diameter ~1.2 μm). The suspensions are sheared with dynamic and continuous stress. Dynamic stress sweeps are used to characterize a dynamic glass transition volume fraction (φg) and a dynamic yield stress (ty*). Both phenomena are understood in terms of activated nave mode coupling theory. The dynamic yield stress increases with volume fraction and scales with a reduced volume fraction φ* as ty* ~ φ *4. Under continuous stress, suspensions discontinuously shear thicken at a critical stress (tt*), which is independent of particle shape and particle interaction. The volume fraction at the onset of thickening (φt) is higher for dumbbell particles compared to spheres. Furthermore, our results suggest that there is a volume fraction where ty = tt, and this volume fraction occurs close to that of random close packing. For larger volume fractions, steady flow is only established through dilation.
- Research Organization:
- Univ. of Illinois at Urbana-Champaign, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division
- Grant/Contract Number:
- FG02-07ER46471; FG02-07ER46453
- OSTI ID:
- 1875157
- Journal Information:
- Journal of Rheology, Journal Name: Journal of Rheology Journal Issue: 5 Vol. 55; ISSN 0148-6055
- Publisher:
- Society of RheologyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Fluctuations in flow produced by competition between apparent wall slip and dilatancy
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journal | March 2014 |
Design of yield-stress fluids: a rheology-to-structure inverse problem
|
journal | January 2017 |
| Shear thickening in concentrated suspensions: phenomenology, mechanisms, and relations to jamming | text | January 2013 |
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