Graphene and graphene nanoplatelets can be used as filler materials especially for polymer reinforcement. The unique properties of quasi two-dimensional graphene, an extraordinary high Young's modulus (approx. 1 TPa) and high fracture strain is shared with carbon nanofillers like quasi one-dimensional carbon nanotubes. Starting from molecular dynamics simulations of graphene nanoribbons and the resulting microphysical behavior we show how to utilize the properties of carbon nanofillers in polymer composites and give proper applications. Functionalization of carbon nanofillers helps in tuning the load transfer between matrix and filler. To arrive at continuum mechanical properties we use a mean-field homogenization approach, neglecting nanoscopic effects at first. Scaling of properties like Young's modulus and yield stress against the parameters aspect ratio, filler content and filler Young's modulus can be predicted with the help of this method. Understanding of additional nanoscopic effects can be improved in the context of mean-field results.
