In this study, we employ overdamped Brownian dynamics simulations to investigate transient colloidal gels formed through Lennard-Jones attractions. Systems with volume fractions ϕ = 0.07–0.13 were examined to assess how concentration controls gel formation, structural connectivity, and mechanical response. It was found that gelation proceeded through a universal three-stage pathway—rapid cluster formation, slower restructuring, and network arrest—whose timescales and energy minima depended systematically on ϕ. Structural analysis via contact number and radial distribution functions revealed a transition from tenuous, fractal networks at low ϕ to dense, highly coordinated networks exhibiting frustration-limited packing at high ϕ. Steady shear measurements showed strong shear-thinning behavior for all systems and a monotonic increase in viscosity with ϕ, reflecting enhanced network connectivity and restricted relaxation pathways. Oscillatory shear tests further demonstrated that the gels were strongly elasticity-dominated (G’≫ G”), with linear viscoelastic plateaus that extended and stiffened as ϕ increased, followed by characteristic softening and yielding at larger strains. Together, these results provide a mechanistic link between particle concentration, microstructure, and emergent rheology, demonstrating that Brownian dynamics simulations can reliably capture key features of transient colloidal gels and offer predictive insights into their macroscopic behavior.
Nnyigide et al. (Thu,) studied this question.