Brownian dynamics simulation on the parallel superposition rheology of a colloidal gel

Parallel superposition rheology has been explored using Brownian dynamics simulations on a model colloidal gel by imposing a small amplitude probing oscillation parallel to the main shear flow. This study aims to investigate the constituting principles behind the material functions in parallel superposition rheometry (PSR) and to elucidate the principles behind the structure responses. The viscoelastic spectra under frequency sweeps show that in a high-frequency region, each curve can be superimposed onto a single master curve using horizontal shift factors equal to viscosity which is a reminiscence of time-shear rate superposition in orthogonal superposition rheometry. This corresponds to the region where a parallel superposition analysis can be adequately performed as the shear rate controls the viscoelastic spectra of the gel independently from probing perturbation. On the other hand,…