Simulated structure of mixed particle gels

Abstract

The structure of mixed particle gels is investigated by means of a Brownian dynamics simulation in two dimensions. The model takes account of differing attractive or repulsive interactions between like and unlike particles as well as differing rates of irreversible bond formation. Data relating to network structure and porosity of the simulated gels are reported for various combinations of input parameters for binary systems of equal-sized particles. In systems with a net repulsive interaction between the unlike particles, the resulting heterogeneity of the network is sensitively dependent on the relative rates of cross-linking and liquid–liquid phase separation. In systems containing a mixture of gelling and non-gelling components, the nature of the network structure and its rate of formation are dependent on the balance between the different kinds of non-bonded pair interactions. The model has applicability to cross-linked mixed protein gels and mixed protein layers at fluid interfaces.