The influence of graphene on the dynamic mechanical behaviour of shear thickening fluids

The viscosity and shear thickening efficiency of the nanoparticle-based shear thickening fluids (STFs) were influenced by hydrodynamic lubrication force between nanoparticles. To enhance such an influence and improve the performance of STF, graphene was adopted to reinforce SiO₂ nanoparticle-based STF in this paper. The viscosity of the reinforced STF was improved obviously by graphene, which makes an increase of 30% compared to the pure STF. In order to characterize the influence of graphene on the flow stress of STF at high strain rates, a split Hopkinson pressure bar was implemented to test the dynamic compressive mechanical properties at strain rates in the range from 3 × 10³ to 10⁴/s. The results showed that graphene has a significant influence on the flow stress of reinforced STF at different strain rates compared to the pure STF, and the effects of the strain rate and graphene volume fraction on the flow stress were analyzed. Based on the hydrodynamic lubrication force theory, the attribution done by grahpene to the hydrodynamic lubrication force in STF was discussed. The results of the paper provide an efficient way to develop a novel STF with high shear thickening efficiency.