Carbon fiber skeleton/silver nanowires composites with tunable negative permittivity behavior

With the development of periodic metamaterials, more attention has been paid to negative permittivity behavior due to great potential applications. In this paper, silver nanowires (AgNWs) were introduced to the porous carbon fibers (CFS) by an impregnation process to prepare CFS/AgNWs composites with different content of AgNWs and the dielectric property was investigated. With the formation of conductive network, the Drude-like negative permittivity was observed in CFS/AgNWs composites. With the increase of AgNWs, the connectivity of conductive network became enhanced, the conductivity gradually increases, and the absolute value of the negative dielectric constant also increases to 8.9 × 104, which was ascribed to the enhancement of electron density of the composite material. Further investigation revealed that the inductive characteristic was responsible for the negative permittivity.