Brownian dynamics simulations of filled particle gels

Abstract

The structure and small-deformation shear rheology of mixed particle gels is investigated by means of Brownian dynamics simulation. The simulation model accounts for gelation through the formation of flexible, irreversible bonds between the particles. Larger particles are added to a solution of smaller particles which themselves form a network. If the larger ‘filler’ particles are incorporated into that network, they increase the gel strength. If equal volumes of filler particles are added, smaller particles have a bigger effect than larger ones. These findings agree qualitatively with experimental results reported in the literature. Filler particles that do not interact with the network have very little effect on the gelation process or the rheology of the network. Only very large particles show a small effect on the shear modulus.