Effects of Nanoparticle Configurations on Mechanical Properties of Polymer Nanocomposites Using Coarse-Grained Molecular Dynamics

Polymer nanocomposites are versatile materials with enhanced properties due to nanofillers like nanoplatelets, nanofibers, and nanoparticles. Advances in manufacturing have introduced novel nanoparticle configurations, such as porous and corrugated structures, but their impact on mechanical properties remains unclear. We address this using coarse-grained molecular dynamics simulations of polymethyl methacrylate nanocomposites with smooth, corrugated, and porous nanoparticles. Quasi-static tensile and shear tests reveal that increasing interfacial interaction enhances mechanical properties across all nanocomposites. Porous nanoparticles provide the greatest reinforcement effect, which is due to the superior confinement of polymer chains, as demonstrated by local molecular stiffness and mean square displacement analyses. Corrugated nanoparticles also outperform smooth ones. Additionally, our results on dynamic moduli characterized through small amplitude oscillatory shear show that porous nanoparticles enhance both storage and loss moduli of the nanocomposites, overcoming the usual tradeoff between stiffness and damping. This is largely attributed to the enhanced dynamic heterogeneity observed in porous cases. Our findings offer valuable insights for designing advanced polymer nanocomposites through innovative nanoparticle engineering.