Investigating the Interaction of Two Bottlebrush Polymer Grafted Nanoparticles: Effects of Stiffness and Grafting density of polymer

Bottlebrush Polymer Grafted Nanoparticles (BPGNs) are synthesized to effectively control the nanoparticle within a polymer matrix and have important applications in nano-based optical materials, medical particles, and nano electronic devices. In this work, we studied the interaction between two BPGNs when one BPGN's chain approaches the core of another nanoparticle. To save simulation costs, an implicit solvent condition and coarse-grained model were adopted, and the stiffness of the backbone chain was controlled by the implicit solvent condition of the side chains. Under good solvent conditions and high grafting density, the simulation results show that the approach to the core was faster compared to the bad solvent and low polymer grafting conditions. Additionally, a steric repulsion region caused by osmotic pressure was found under the good solvent condition, causing chain separation. Finally, we conducted simulations to investigate the effect of the stiffness of the backbone chain by giving an angle potential to the backbone chain. Increasing the energy coefficient resulted in faster core approach and the effect of osmotic pressure was more pronounced. This study proposes more efficient ways to induce gelation when self-assembling BPGNs.