Preparation of nanoparticles grafted with bimodal-bidisperse polymers in nanocomposite

Because of the important application in nanocomposite materials, the preparation of nanoparticles (NPs) tethered with bimodal bidispersed polymer chains via grafting-from strategy is studied by coarse-grained molecular dynamics simulations combined with the stochastic reaction model. We design three conventional scenarios for preparing these NPs, i.e., a two-step grafting-from process with the long chains grow first followed by the short chains, a similar two-step grafting-from process with the short chains grow first followed by the long chains, and a one-step scenario to graft both chains concurrently. We find the priority of chain growth greatly influences the grafting density of the finally prepared nanoparticles. The simulations strongly suggest that for obtaining a medium and comparable grafting density of both short and long chains in experiment, an ideal strategy is activating both the initiators simultaneously or grafting the long chains firstly. We also find that in the one-step scenario, the simultaneously growing short and long chains have complicated mutual effects on each other. Our study helps to better understand the kinetics during the preparation of bimodal bidisperse-polymer grafted NP and could act as a guide to better design and improve the performance of polymer nanocomposites.