Probing the intensity of dilatancy of high performance shear-thickening fluids comprising silica in polyethylene glycol

Abstract

High-performance shear thickening fluids (STFs) due to its dilatant behaviour find appositeness in any applications which require the effective dissipation of energy without losing stiffness. The nature of particles and the medium along with the particle loading fraction affect significantly the important characteristics of dilatancy such as the critical shear-rate, critical viscosity and the relative peak viscosity. The STFs, in this study showed a faster onset of shear thickening with increasing particle loading fraction, particle size and viscosity of carrier fluid whereas a better intensity of shear thickening was obtained at elevated magnitudes of medium viscosity and particle loading fraction only. These observations have been duly explained from the point of hydrocluster theory elucidating the effects of perikinetic and orthokinetic aggregation. The obtained data were fitted on existing apparent viscosity-function models which construed the dilatancy of the fluid further and defined the system for continuous and discontinuous shear thickening behaviours.