We demonstrate how tracer microrheology methods can be extended to study submicron scale variations in the viscoelastic response of soft materials; in particular, a semidilute solution of lambda-DNA. The polymer concentration is depleted near the surfaces of the tracer particles, within a distance comparable to the polymer correlation length. The rheology of this microscopic layer alters the tr...

Recent progresses in understanding the behavior of dense granular flows are presented. After presenting a bulk rheology of granular materials, I focus on the new developments to account for non-local effects, and on ongoing research concerning the surface rheology and the evolution of mechanical properties for heterogeneous systems.

Rheological behavior, including linear and nonlinear, as well as transient rheology of nanocrystalline cellulose (NCC) suspensions was studied in this work. Two kinds of polymer solutions, aqueous poly(vinyl alcohol) (PVA) with flexible chain structure and aqueous carboxymethyl cellulose (CMC) with semi-rigid chain structure, were used as the suspension media to further explore the role that th...

Mastication is continually modified throughout the chewing sequence in response to the texture of the food. The aim of this work was to compare the effects of an increase in hardness of two model food types, presenting either elastic or plastic rheological properties, on mastication. Each model food type consisted of four products of different hardness. Sensory testing experiments conducted wit...

We show that bent-core liquid crystalline materials exhibit non-Newtonian flow in their optically isotropic liquid phase. We conjecture that this behavior is due to the existence of nanostructured, fluctuating clusters composed of a few smectic-like layers. Shear alignment of these clusters explains the shear thinning observed in bent-core liquid crystals having either a nematic phase or nonmod...

The instrument for determination the texture with air puff’s Foodtexture Puff Device (FPD) is a new device that yields contactless, fast, easy and non-destructive rheological measurements of food products. The instrument applies a controlled air pulse to the surface of a food product, while a laser distance sensor measures the deformation. This approach can be considered as an alternative metho...

Dispersions of colloidal particles in aqueous media are widely investigated because of their use in many industrial applications (foods, pharmaceuticals, cosmetics, paints, etc.). Acid-hydrolyzed chitin has been reported to spontaneously disperse into colloidal rod-like crystalline particles, which can form rigid structures. Such colloidal dispersions of acid-degraded chitin can undergo an isot...

The rheological properties and microstructure of buffalo yoghurt were investigated and compared to bovine yoghurt. Buffalo yoghurt exhibited a greater degree of thixotropy and a higher level of syneresis. These differences can be linked to the underlying microstructure of the yoghurt, which is more porous and contains bigger fat globules compared to bovine yoghurt. This study shows how milk pro...

Synthetic polymer fluids are becoming a popular replacement for bentonite slurries to support excavations for deep foundation elements. However, the rheological properties of the polymer fluids used in excavation support have not been studied in detail, and there is currently confusion about the choice of mathematical models for this type of fluid. To advance the current state of knowledge, a l...

Objective The inconsistent results within the current literature regarding the efficacy of intra-articular-hyaluronic acid (IA-HA) for the treatment of knee osteoarthritis (OA) have been suggested to be due to intrinsic differences between individual HA products. The purpose of this investigation is to define the rheological differences between currently available HA products in the United Stat...