Ultraweakly low-dispersion epsilon-negative response of GR-CNT/PVDF ternary metacomposites

The epsilon-negative (ε' < 0) response displayed by metacomposites offers notable potential for diverse applications in the design of dielectric and electromagnetic (EM) devices, underpinned by novel principles. However, achieving a weakly low-dispersion ε′-negative performance within the radio frequency (RF) band remains challenging. In this study, we bypassed this issue by constructing three-dimensional (3D) conductive networks through the integration of graphene (GR) and carbon nanotubes (CNT) with polyvinylidene fluoride (PVDF) serving as the matrix material. Leveraging the modifiable GR-CNT network, a ε′-negative response at approximately −20 was attained spanning the 100 MHz-1 GHz range. This ultraweak ε′-negative response was attributed to the formation of a moderate plasmonic state of free carriers within the metacomposites. Further, simulations were conducted, assessing the electric field vector distribution of the ε′-negative materials, revealing promising EM shielding performance. Concurrently, this investigation elucidates the RF ε′-negative response mechanism, paving the way for the practical application of metacomposites.