MD Modeling of Epoxy-base Nanocomposites Reinforced with Functionalized Graphene Nanoplatelets

摘要

The impact on the mechanical properties of aerospace epoxy materials reinforcedwith pristine Graphene Nanoplatelets (GNP), highly concentrated Graphene Oxide(GO), and Functionalized Graphene Oxide (FGO) has been investigated in this study.Molecular Dynamics (MD) using a reactive force field (ReaxFF) has been employedin predicting the effective mechanical properties of the interphase region of the threeproposed nanocomposite materials at the nanoscale level. A systematiccomputational approach to simulate the reinforcing nanoplatelets and probe theirinfluence on the mechanical properties of the epoxy matrix are included in this study.The nanoscale outcome indicates a significant degradation in the in-plane elasticYoung’s (decreased by ～89%) and shear (decreased by ～72.5%) moduli of thenanocomposite when introducing large amounts of oxygen and functional groups tothe robust sp2 structure of the GNP. However, the wrinkled morphology of GO andFGO improves the nanoplatelet-matrix interlocking mechanism which produces asignificant improvement in the out-of-plane shear modulus (increased by ～95%). Theinfluence of the nanoplatelet content and aspect ratio on the mechanical response ofthe nanocomposites has also been determined in this study. Generally, the predictedmechanical response of the bulk nanocomposite materials demonstrates animprovement with increasing nanoplatelet content and aspect ratio. The results showgood agreement with experimental data available from the literature.