(726d) Comparison of Coarse-Grained Approaches in Predicting Polymer Nanocomposite Phase Behavior
In conducting the direct comparison, we are able to systematically study the impact of many-body effects, random versus uniform grafting of polymers on the nanoparticles, and thermal fluctuations on the large-scale phase behavior of grafted nanoparticles in a polymer matrix. Additionally, we provide a qualitative comparison of the three methods to experiments consisting of polystyrene grafted gold nanorods in a polymethyl methacrylate matrix. For large matrix molecular weights, when the nanoparticles are randomly initialized in the non-equilibrium method, the nanoparticles coarsen into larger clusters, similar to the experiments. However, when the non-equilibrium simulations are initially biased as a single aggregate, the particles remain macrophase separated from the matrix over the course of the simulation. This indicates the experiments are in a non-equilibrium state. In using these coarse-grained approaches, we are able to describe and discern the thermodynamic versus non-equilibrium nature of PNCs.