Exploring the mechanical properties of two-dimensional carbon-nitride polymer nanocomposites by molecular dynamics simulations

The enhancement of mechanical properties of polymeric materials by the addition of strong nanomaterials is currently among the most appealing routes for the application of polymers in structural components and nanoelectronics. Carbon-nitride nanomembranes have attracted remarkable attention due to their outstanding physical properties in recent years. In this study, the role of graphene (GN) and various carbon-nitride (CxNy) nanosheets on the mechanical reinforcement of P3HT polymer nanocomposites is systematically investigated by conducting extensive molecular dynamics (MD) simulations. We first elaborately examine the mechanical responses of pristine nanosheets. Next, we construct large atomistic models of polymer nanocomposites to examine the effective mechanical properties as a function of nanofillers content. To this end, the interfacial strength and cohesive zone properties between various nanosheets and the polymer are investigated. With the aid of constructed models, we explore the underlying mechanisms of mechanical reinforcement and formation of initial crack and its correlation with interface strength between nanosheets and polymer. Furthermore, the effects of nanoporosity in the nanomembranes lattice and the resulting interfacial strength and mechanical response are discussed. Acquired findings provide a useful vision for understanding the mechanical/failure responses of polymer nanocomposites reinforced with carbon-nitride nanosheets.