Related papers: A multi-axis confocal rheoscope for studying shear…
Using a novel bi-axial confocal rheoscope, we investigate the structure and rheology of sheared colloidal suspensions under confinement. Consistent with previous work [X. Cheng \textit{et al., Proc. Natl. Acad. Sci. U. S. A.}, 2011, 109,…
We develop and test a rheo-optical platform based on a two-axes, parallel plates shear cell coupled to an optical microscope and a photon correlation imaging setup, for simultaneous investigation of the rheological response and the…
The present study proposes a novel full-field extensional rheo-optical technique to investigate the relationship between the rheological properties and internal structural deformation of complex fluids under uniaxial extensional flow.…
The rheology of dense amorphous materials under large shear strain is not fully understood, partly due to the difficulty of directly viewing the microscopic details of such materials. We use a colloidal suspension to simulate amorphous…
The present study proposes a novel and simple rheo-optical technique to investigate the relation between the rheology of complex fluids and their internal structural deformation under uniaxial extensional flow. The macroscale results of…
We present here a novel cantilever based apparatus to perform translational stress or strain controlled rheology in very soft solids, and obtain simultaneous confocal imaging of the 3 dimensional microstructure. The stress is measured using…
We present recent advances in the instrumentation and analysis methods for quantitative imaging of concentrated colloidal suspensions under flow. After a brief review of colloidal imaging, we describe various flow geometries for two and and…
A confined colloidal glass, under the imposition of a uniform shear stress, is investigated using numerical simulations. Both at macro- and microscales, the consequent dynamics during the onset of flow is studied. When the imposed stress is…
We review recent advances in imaging the flow of concentrated suspensions, focussing on the use of confocal microscopy to obtain time-resolved information on the single-particle level in these systems. After motivating the need for…
In this study, the concept of rheo-optics is applied that explores the flow birefringence caused by stress components along the optical axis of the camera since it is often overlooked in the traditional theories of photoelastic flow…
Using fast confocal microscopy we image the three-dimensional dynamics of particles in a yielded hard-sphere colloidal glass under steady shear. The structural relaxation, observed in regions with uniform shear, is nearly isotropic but is…
We develop and thoroughly test a stress-controlled, parallel plates shear cell that can be coupled to an optical microscope or a small angle light scattering setup, for simultaneous investigation of the rheological properties and the…
To investigate the interplay between microscopic dynamics and macroscopic rheology in soft matter, we couple a stress-controlled-rheometer equipped with a Couette cell to a light scattering setup in the imaging geometry, which allows us to…
Using high-speed confocal microscopy, we measure the particle positions in a colloidal suspension under large amplitude oscillatory shear. Using the particle positions we quantify the in situ anisotropy of the pair-correlation function -- a…
Oscillatory shear tests are widely used in rheology to characterize the linear and non-linear mechanical response of complex fluids, including the yielding transition. There is an increasing urge to acquire detailed knowledge of the…
We use particle-based simulation to study the rheology of dense suspensions comprising mixtures of small colloids and larger grains, which exhibit shear thinning at low shear rates and shear thickening at high shear rates. By systematically…
Dense suspensions of soft colloidal particles display a broad range of physical and rheological properties which are still far from being fully understood. To elucidate the role of deformability on colloidal flow, we employ computer…
We probe the relation between shear induced structural relaxation and rheology in experiments on sheared two-dimensional foams. The relaxation time, which marks the crossover to diffusive bubble motion, is found to scale non-trivially with…
Rheology aims at quantifying the response of materials to mechanical forcing. However, standard rheometers provide only global macroscopic quantities, such as viscoelastic moduli. They fail to capture the heterogeneous flow of soft…
The present study investigated the flow birefringence induced by shear components along a camera's optical axis, which has been neglected in conventional theories of photoelastic measurements. Measurements were conducted for a wide range of…