Rheological study of the effects of size/shape of graphene oxide and SiO2 nanoparticles on shear thickening behaviour of polyethylene glycol 400-based fluid: molecular dynamics simulation

In this computational study, the effect of the shape and size of graphene oxide (GO) and SiO2 nanoparticles on the shear thickening Behaviour of the fluids was reported with the molecular dynamics (MD) approach. For this purpose, the viscosity of fluids with C, Si, O, and H atomic arrangements was determined by Tersoff and Lenard-Jones (LJ) interatomic force fields. Atomic stability of the simulated structures was detected after 1.000.000 time-steps, demonstrating the validity of the PEG-400-based STF. Additionally, MD simulation results indicated that addition of zigzag GO and cubic SiO2 nanoparticles to the pristine fluid would maximise the viscosity of this atomic structure. Numerically, by adding these nanostructures, the viscosity of the simulated fluid was converged to 88 Pa. s and 94 Pa. s, respectively. The jamming viscosity (discontinuous shear-thickening) changes occurred in 70 and 80 s(-1) shear rates by adding GO and SiO2 nanoparticles to the pristine fluid.

Automated summary

In this computational study, the effect of the shape and size of graphene oxide (GO) and SiO2 nanoparticles on the shear thickening behavior of fluids was investigated using molecular dynamics simulations (MD). The results showed that the addition of zigzag GO and cubic SiO2 nanoparticles maximized the viscosity of the fluid, leading to jamming viscosity changes at certain shear rates.