Self-assembly of oppositely charged particles in dilute ceramic suspensions: predictive role of simulations

Ceramic suspensions composed of oppositely charged alumina and silica particles are studied experimentally and by means of Brownian dynamics simulations. Alumina and silica particles have quite similar sizes, the former having an average diameter larger by a factor 1.6. The suspension behavior is studied as a function of composition. The aggregation state, the aggregate composition, structural aspects at several length scales and the aggregate growth kinetics are analysed. A good agreement between numerical and experimental results is obtained. The simulations allow us to describe in detail the aggregation process and mechanisms. Simulations appear as an important tool to predict and control the particle assembly in such binary suspensions, whose behaviour depends on several parameters.