Effect of SiO2 Particle Size and Length of Poly(Propylene Glycol) Chain on Rheological Properties of Shear Thickening Fluids

Abstract

The rheological properties of shear thickening fluids based on silica powder of particles size in range 0.10 – 2.80 μm and poly(propylene glycol) of 425, 1000, 2000 g/mol molar mass were investigated. The effect of particle size and the length of the polymeric chain was considered. The objective of this study was to understand basic trends of physicochemical properties of used materials on the onset and the maximum of shear thickening and dilatant effect. Outcome of the research suggested that an increase in the particle size caused a decrease in dilatant effect and shift towards higher shear rate values. Application of carrier fluid of higher molar mass allowed to increase dilatant effect but it resulted in the increase of the initial viscosity of the fluid.

Rheological and Technological Aspects in Designing the Properties of Shear Thickening Fluids

“…Silica is a primary choice as a solid phase for STF production [ 16 , 33 , 34 ], but other raw materials such as corn starch [ 35 ], calcium carbonate [ 36 ], titanium dioxide [ 37 ], polymethyl methacrylate [ 38 ], polystyrene [ 39 ], or ethyl polystyrene acrylate [ 40 ] are also used for this purpose. The continuous phase of an STF is usually ethylene glycol [ 41 , 42 ], poly(ethylene glycol) [ 32 , 43 , 44 ], propylene glycol [ 41 ], or poly(propylene glycol) [ 7 , 45 , 46 , 47 ]. There are also reports on the application of glycerin [ 48 ], ethanol [ 37 ], and even water [ 49 ].…”

Enhancement of thermo‐rheological properties of smart materials based on SiO2 and PPG modificated with expanded graphite

“…It is a result of the larger distance and weaker interactions between particles such as: attractive Van der Waals forces, repulsive electrostatic forces, Brownian motion, force‐distance relation. Thus, it directly caused decrease in viscosity and the dilatant effect . Sufficiently small distance between the particles favor Van der Waals interactions, responsible for the viscosity and fluid flow.…”

Organogels containing immobilized shear thickening fluid and their composites with polyurethane elastomer

“…To examine the influence of polymer network content on rheological properties of the immobilized shear thickening fluids, three samples with various polymer network content were analysed (figure 15). Complex viscosity curves at various strain for all three samples were also determined (figures [16][17][18].…”

“…Although a large number of studies have been made, the detailed mechanism of shear thickening behaviour is still under debate. Properties of shear thickening fluids (STF) are influenced by many factors [13], like temperature [14,15], size of the dispersed phase [16], particle size distribution [17], particle hardness [18], molecular mass of the carrier fluid [12,19] or pH of the suspension [20].…”