Abstract The rheological characterization of a model, nearly ideal thixotropic carbon black suspension first proposed by Dullaert and Mewis (JNNFM 139: 21-30, 2006) is extended to include large amplitude oscillatory shear (LAOS) flow, shear flow reversal, unidirectional LAOS flow (UD-LAOS). We show how this broader data set is useful for validating and improving constitutive models of thixotrop...

Pistachio butter (semi solid paste), which is made from roasted pistachio kernels, is an appropriate alternative to work on because of its high nutritional and economical values. In this study, timedependent flow properties of pistachio butter were determined at two different temperatures (25˚C and 45˚C) for five different formulations (with different levels of emulsifying agents). Forward a...

We have studied the flow induced by a macroscopic spherical particle settling in a Laponite suspension that exhibits a yield-stress, thixotropy and shear-thinning. We show that the fluid thixotropy (or aging) induces an increase with time of both the apparent yield stress and shear-thinning properties but also a breaking of the flow fore-aft symmetry predicted in Hershel-Bulkley fluids (yield-s...

Rheology plays a crucial role in the field of extrusion-based three-dimensional (3D) printing, particularly context hydrogels. Hydrogels have gained popularity 3D printing due to their potential applications tissue engineering, regenerative medicine, and drug delivery. The rheological properties material significant impact on its behaviour throughout process, including extrudability, shape rete...

The non-Newtonian shear rheology of colloidal dispersions is the result of the competition and balance between hydrodynamic (dissipative) and thermodynamic (conservative) forces that lead to a nonequilibrium microstructure under flow. We present the first experimental measurements of the shear induced microstructure of a concentrated, near hard-sphere colloidal dispersion through the shear thic...

Time-dependent rheological properties and thixotropy of reconstituted debris-flows samples taken from channel bank deposits are examined using a commercial rheometer equipped with vane rotor geometric system. Sweep tests creep were carried out involving mixtures having different grain concentrations ranging between 50% 58%. Different initial conditions the considered in order to analyze effects...

In this study, we characterized and modeled the rheology of TEMPO-oxidized cellulose nanofibril (NFC) aqueous suspensions with electrostatically stabilized and unflocculated nanofibrous structures. These colloidal suspensions of slender and wavy nanofibers exhibited a yield stress and a shear thinning behavior at low and high shear rates, respectively. Both the shear yield stress and the consis...

A computational fluid dynamics (CFD) model that evaluates mechanical mixing in a full-scale anaerobic digester was developed to investigate the influence of sewage sludge rheology on the steady-state digester performance. Mechanical mixing is provided through an impeller located in a draft tube. Use is made of the Multiple Reference Frame model to incorporate the rotating impeller. The non-Newt...

Steady state viscosity and thixotropy of hydrophobically modified hydroxyethyl cellulose ~HMHEC! and nonassociative cellulose water solutions are studied. Although all the samples are shear thinning, only the HMHEC is thixotropic, since the migration of hydrophobes to micelles is controlled by diffusion. The Cross model fits steady state curves. The Mewis model, a phenomenological model that pr...

Additives were tested for their ability to modify the rheology of lignocellulosic biomass. Additive types included water-soluble polymers (WSPs), surfactants, and fine particles. WSPs were the most effective rheological modifiers, reducing yield stresses of concentrated biomass by 60–80% for additive concentrations of 1–2 wt. % (based on mass of dry biomass solids). Yield stress and plastic vis...