Synergistic Effects of Carbon Nanotubes on Negative Dielectric Properties of Graphene-Phenolic Resin Composites

Abstract

Carbon nanotubes-graphene-phenolic resin (CNTs-GR-PR) composites are first prepared to investigate the effects of CNTs on negative dielectric properties of GR-PR composites. The results show that microstructures are easily adjusted by the mass ratio of CNTs to GR and total carbon content, which have an impact on the negative dielectric properties of the composites. The negative permittivity from the CNT 1.6 -GR 5 -PR is observed with the total carbon content of 6.6 wt %, attributed to the formation of conductive pathways. Yet the permittivity of the GR 6.6 -PR still remains positive, indicating that the addition of CNTs is beneficial to the appearance of negative permittivity and shows the synergistic effect. When the total carbon content exceeds 6.6 wt %, the addition of an appropriate amount of CNTs (the mass ratio of CNTs to GR is 0.33:1 and 1:1) improves the alternating conductivity (σ ac ) and imaginary permittivity (ε″), resulting from the connectivity improvement in conductive phases. As compared to the dielectric loss tangent (tan δ) from the GR 8 -PR (below 35), the tan δ of CNT 4 -GR 4 -PR is higher over the whole frequency and above 100 before 400 MHz, indicating the appropriate addition of CNTs enhances the dielectric loss.

Hydrosoluble Graphene/Polyvinyl Alcohol Membranous Composites with Negative Permittivity Behavior

“…In other words, the negative permittivity should be related to the inductive character 58,59. A similar phenomenon was also observed in Cu/Y 3 Fe 5 O 12 ,60 Fe/epoxy resin61 and carbon nanotubes/graphene/phenolic resin composites 62…”

“…[58,59] A similar phenomenon was also observed in Cu/Y 3 Fe 5 O 12 , [60] Fe/epoxy resin [61] and carbon nanotubes/graphene/phenolic resin composites. [62]…”

Magnetic negative permittivity with dielectric resonance in random Fe3O4@graphene-phenolic resin composites

“…In our previous work, GR-based conventional metacomposites with negative permittivity were designed, such as GR-phenolic resin (PR) and GR-acrylic polyurethane composites [20][21][22]. However, due to the fact that GR lacks magnetic properties, the applications of these conventional metacomposites have been limited in some fields, such as magnetic recording systems, computer memory, and magnetoresistance sensors [23][24][25][26][27].…”

Carbon nanofibers/polypyrrole nano metacomposites

“…The metamaterials without periodic ordered blocks are so‐called “intrinsic metamaterials,” whose performances significantly depend on their composition and component distribution. Intrinsic metamaterials developed rapidly in metal composites like alumina composites, silver composites, and polymer composites like phenolic resin composites . For the rapid development of metamaterials today, researchers have also investigated CNFs in the application of metamaterials.…”

“…Intrinsic metamaterials developed rapidly in metal composites like alumina composites, 3 silver composites, 4 and polymer composites like phenolic resin composites. [5][6][7] For the rapid development of metamaterials today, researchers have also investigated CNFs in the application of metamaterials. In 2009, Zhong and coworkers reported that CNFs/polyether imide (PEI) composites with 2.0 wt % CNFs possessed negative permittivity.…”