Conductivity and Shielding Ability of Multicomponent Nanocomposites

Conductive polymer nanocomposites have been developed as an interesting class of materials due to their superior properties. The volume fraction of nanofillers beyond which the sharp rise in the conductivity happens is called the percolation threshold. To make it cost efficient while retaining the performance, one approach is to use mixture of nanofillers.
First, Monte Carlo simulations of the systems comprising a mixture of spheroidal nanofillers using the critical path based tunneling-percolation model are used to examine the effects on the electrical conductivity. The model predictions are found to match well with excluded volume based analytical formulations.
Next, the electromagnetic interference shielding effectiveness of a mixture of fillers is investigated in the X-band frequency range using finite element modeling. The simulation results are shown to agree well with the experimental data. The filler alignment and size polydispersity are found to have a significant effect on the shielding ability.
Finally, the conductivity and shielding ability of multicomponent nanocomposites are compared with monocomponent nanocomposites. The results can guide how to achieve an enhanced electrical conductivity and shielding ability with lowest volume fractions of fillers.