Aggregation and Cluster Composition in Latex-Pigment Mixtures: A Particle Simulation Study

Colloidal suspensions have many applications, for example paints and coatings. Using particle dynamics simulations, we aim to provide fundamental molecular-level insight into the formation of composites and aggregates in high-end latex-based coatings. The paint suspension is composed of latex and multi-layered pigment particles, as well as dispersants and other additives. This complex mixture complicates the cross- and self-interactions of all components, thus affecting aggregation. We provide insight into the properties of paint coatings by investigating the interactions that affect the aggregation and formation of small clusters in suspension. We vary the amount of latex compared to pigment in the system, the total volume fraction of latex and pigment, and the strength of the cross- and self-interactions. Using simple physical models for effective interactions between particles, we elucidate how the propensity to aggregate and the local latex-pigment environment changes. We also investigate cluster fractal dimension, composition, and kinetics.