Dispersion patterns of graphene and carbon nanotubes in ceramic matrix composites

The dispersion properties of mechanically exfoliated few layer graphene flakes within the silicon nitride ceramic matrix have been compared with those of multi-walled carbon nanotubes. Small angle neutron scattering experiments have been involved to provide information on the dispersion of the nano-scale carbon fillers throughout the entire volume of the samples. The neutron scattering data revealed a strikingly different distribution pattern for graphene and nanotubes in the ceramic matrix. While carbon nanotubes were found to be present mainly in the form of small aggregate structures, few-layer graphene flakes have been uniformly dispersed, under the same processing conditions. The observed dispersion properties have also been correlated with the mechanical properties of the resulting composites.