Dilatancy in dense suspensions of model hard-sphere-like colloids under shear and extensional flow
arXiv:2007.04141 · doi:10.1122/1.5143653
Abstract
Dense suspensions of model hard-sphere-like colloids, with different particle sizes, are examined experimentally in the glass state, under shear and extensional rheology. Under steady shear flow we detect Discontinuous Shear Thickening (DST) above a critical shear rate. Start-up shear experiments show stress overshoots in the vicinity of the onset of DST related with a change in microscopic morphology, as the sample shows dilatancy effects. The analysis of the normal stress together with direct sample observation by high speed camera, indicates the appearance of positive N1 and dilation behavior at the shear thickening onset. Dilatancy effects are detected also under extensional flow. The latter was studied through capillary breakup and filament stretching experimental setups, where liquid-like response is seen for strain rate lower than a critical strain rate and solid like-behavior for higher strain rates. Monitoring the filament thinning processes under different conditions (volume fractions and strain rates) we have created a state diagram where all responses of a hard-sphere suspension (Newtonian, shear thinning, shear thickening, dilatant) are shown. We finally compare the shear thickening response of these hard-sphere-like suspensions and glasses in shear with that in extensional flow.
References in corpus (22)
- Jamming, Force Chains and Fragile Matter
- Discontinuous Shear Thickening of Frictional Hard-Sphere Suspensions
- Shear thickening in concentrated suspensions: phenomenology, mechanisms, and relations to jamming
- Discontinuous shear thickening without inertia in dense non-Brownian suspensions
- Hydrodynamic and contact contributions to shear thickening in colloidal suspensions
- Shear thickening of cornstarch suspensions as a re-entrant jamming transition
- A unified description of the rheology of hard-particle suspensions
- Microscopic mechanism for the shear-thickening of non-Brownian suspensions
- In Search of Colloidal Hard Spheres
- A dynamic jamming point for shear thickening suspensions
- A rheological signature of frictional interactions in shear thickening suspensions
- On the existence of a simple yield stress fluid behavior
- Jamming, two-fluid behaviour and 'self-filtration' in concentrated particulate suspensions
- Shear thickening in granular suspensions: inter-particle friction and dynamically correlated clusters
- A rheological state diagram for rough colloids in shear flow
- Unsteady flow and particle migration in dense, non-Brownian suspensions
- Dilatancy in the flow and fracture of stretched colloidal suspensions
- Dilatancy, Jamming, and the Physics of Granulation
- Start-up Shear of Concentrated Colloidal Hard Spheres: Stresses, Dynamics and Structure
- System-spanning dynamically jammed region in response to impact of cornstarch and water suspensions
- Jamming transitions in a schematic model of suspension rheology
- Dilatancy in dense suspensions of model hard-sphere-like colloids under shear and extensional flow