The effects of interparticle interactions and particle size on reversible shear thickening: Hard-sphere colloidal dispersions

Abstract

A comparison between the effects of two colloidal stabilizing methods ͑electrostatic versus Brownian͒ on the reversible shear thickening transition in concentrated colloidal suspensions is explored. Five suspensions of monodisperse silica are synthesized via the Stöber synthesis and dispersed in an index matched organic solvent to minimize van der Waals interactions. The residual surface charge is neutralized with nitric acid (c HNO 3 Ϸ 0.1 M͒ resulting in a near hard-sphere interaction that is confirmed by small angle neutron scattering measurements across a range of volume fractions. Rheological measurements demonstrate the effects of neutralization on the low shear and high shear rheology, which show that the onset of shear thickening moves to lower applied shear stresses and scales inversely with particle size cubed, in agreement with theory. Quantitative comparisons of both the low shear viscosity and the critical stress for shear thickening to predictions for hard spheres and literature data demonstrate the extreme sensitivity of high shear rheology to the surface properties in concentrated suspensions.

Dynamic response of shear thickening fluid under laser induced shock

“…Also, the deformation or crack of the hard-sphere particles as well as the volume compressibility of the particles and the polyethylene glycol could be neglected. In addition, the previous studies 8,19,[27][28][29][30] showed that critical conditions were required to occur the shear thickening in STF. A minimum strain might be not obtained in several tens of nanoseconds to occur the shear thickening behavior when the particle velocity decays to a relative low value, leading to the saturations of the stress attenuation and the energy absorption in the STF.…”

Dilatancy in the flow and fracture of stretched colloidal suspensions

“…Such interactions could greatly influence the flow behaviour, as they do in strongly aggregating colloids at lower densities 10 . The fundamental physics of colloidal jamming is therefore better addressed in model systems of nearly hard-sphere particles [3][4][5][6] , which are forced into contact by external stresses without the added complexities of ill-defined interactions.…”

Stratification Learning: Detecting Mixed Density and Dimensionality in High Dimensional Point Clouds (PREPRINT)

“…Included in this study are fabrics treated with STFs. STFs are materials that are flowable at low stress levels but transition to a solid-like state when subjected to higher stresses (1)(2). Previous experiments have shown that adding STFs to high performance fabrics such as nylon and Kevlar * can increase the protective properties of these fabrics, especially against puncturing threats (3-6).…”