Morphological and mechanical properties of graphene-reinforced PMMA nanocomposites using a multiscale analysis

In this study, a multiscale simulation analysis combining mesoscale dissipative particle dynamics (DPD) method and continuum mechanics based finite element method (FEM) is adopted to study the morphological and mechanical properties of graphene-reinforced poly(methyl methacrylate) (PMMA) nanocomposites. Specifically, DPD simulations are performed for PMMA nanocomposite systems with graphene of different surface chemistries (i.e., GN, FGN and PMMA@FGN) and different process routines. It is found that the covalently functionalised PMMA@FGN/PMMA system can achieve a better dispersion than that of untreated GN/PMMA system, which is attributed to the intercalated coating molecules between graphene nanofillers. However, increasing shear rate during processing may not result in a better nanofiller dispersion or orientation as expected. The DPD microstructures of nanocomposite systems are subsequently mapped onto a 3D finite element representative volume element (RVE). The mechanical properties obtained from FEM match reasonably well with those from experiments in literature, which further demonstrated the effectiveness of the proposed multiscale approach.