Multi-scale finite element analysis of graphene/polymer nanocomposites: electrical performance

This paper presents a multi-scale, multi-physics finite element model (FEM) simulating the electrical performance of single layer graphene/insulator under DC loading, which would be easily applied to most cases, extended to a more sophisticated material architecture in respect of being scientifically structured and proven. The approach consists of the creation of a unit cell and a representative volume element (RVE) micro-scale nanocomposite model on a commercially available FE package. The implementation of these models has been considered satisfactory and successful, as the variation of nanocomposite's electrical conductivity in respect to the volume content was in accordance with experimental data. Moreover, the numerical simulation was in accordance with the classical percolation law predictions, while the obtained percolation thresholds in terms of aspect ratio obey the Excluded Volume Theory. The graphene shape was considered in the analysis as a geometric parameter, being proved that the shape does not exhibit any profound effect on the electrical performance of the graphene/insulator nanocomposite. Finally, this model is capable to predict the full percolation response of the nanocomposite and can be applied to any nanocomposite architecture in contrast to general theories that can only estimate the percolation threshold rather than the full response.