Self-diffusion in dispersions of charged colloidal spheres by generalized hydrodynamics

The generalized hydrodynamics formalism for the collective and single particle suspension dynamics is solved for dispersions of strongly interacting particles as a function of surface charge. Both collective and single particle properties are compared to results from large-scale Brownian dynamics simulations, enabling the evaluation of the viscoelastic and short-time approximations for the memory functions. Unlike the short-time approximation, the viscoelastic approximation yields good predictions for time-integrated properties, such as shear viscosity and self-diffusion. However, the simplified dynamics inherent in the viscoelastic ansatz are found to be too crude to fully capture the time-evolution of the dynamic structure. At high surface charge the viscoelastic ansatz results in a critical slowing of the self and collective dynamics similar to observations near the ideal glass transition. This behavior is attributed to the self and collective dynamics similar to observations near the ideal glass transition. This behavior is attributed to the self-consistent nature of the solution for the dynamics.