Carbon nanotubes / epoxy resin metacomposites with adjustable radio-frequency negative permittivity and low dielectric loss

Abstract Metacomposites with negative permittivity always suffer from high dielectric loss tangent, which limits their match with positive permittivity materials and magnetic components. In this work, carbon nanotubes/ epoxy resin composites with adjustable negative permittivity and low dielectric loss have been prepared by pre-curing method. The phenomenon of negative permittivity is derived from low frequency plasmon resonance of free electrons through analyzing the microstructures and resistivity of the composites detailed. Consequently, the negative permittivity of the composites could be adjusted effectively by simply changing the content of carbon nanotubes. Moreover, the low dielectric loss tangent is achieved for introducing the epoxy resin which reduces the molecular dipole and interface polarization. This work provides pre-curing method to fabricate metacomposites with adjustable negative permittivity and low dielectric loss and can expand the potential applications of metamaterials.