Three-dimensional graphene network supported by poly phenylene sulfide with negative permittivity at radio-frequency

Percolative composites with negative permittivity can be promising candidates for metamaterials, but there is still a need about efficient method to adjust the permittivity value. Here graphene/poly phenylene sulfide composites were prepared and the dielectric property was studied. By gradually increasing the graphene content, three-dimensional conductive network could be constructed, accompanied by a change in the conductive mechanism from hopping conduction to metal-like conduction. Negative permittivity was achieved, and the Drude model indicated that negative permittivity came from the plasma oscillation in graphene network. The equivalent circuit analysis demonstrated that interconnection of graphene was the most crucial factor to adjust the negative permittivity value. That is, negative permittivity value can be effectively adjusted by graphene content. These findings may pave a way to simply and efficiently control negative permittivity and imply promising applications in modern electrical and electronic industries.