Nanoparticle aggregation in the presence of a block copolymer.

By employing dissipative particle dynamics simulations, we investigated the cooperative phase behavior of composites containing diblock copolymer molecules and nanoparticles. The nanoparticles and their aggregates are located either in the domains generated by each of the two kinds of segments of the block copolymer and/or at their interface. Various conditions, such as the interactions between nanoparticles, the interactions between them and the segments of the block copolymer, the interactions between the segments of the block copolymer, and the volume ratio of nanoparticles to block copolymer, have been changed to gather information about nanoparticle aggregation and block copolymer/nanoparticles morphology building. The dynamics of nanoparticles aggregation and the evolution of the morphology of the block copolymer have been followed. Our findings have identified two critical repulsive interactions regarding nanoparticle aggregation, one between nanoparticles and the other between the segments of the block copolymer and nanoparticles. Aggregates have been generated for repulsive interactions larger than the former critical value or smaller than the latter one.