CC BY-NC-ND 4.0 UnportedAmeli, A.Arjmand, M.Pötschke, PetraKrause, BeateSundararaj, U.2023-10-132023-10-132016https://oa.tib.eu/renate/handle/123456789/12481https://doi.org/10.34657/11511This study reports on nitrogen-doped carbon nanotube (N-CNT)/polymer nanocomposites exhibiting relatively high and frequency independent real permittivity (ϵ′) together with low dielectric loss (tan δ). N-CNTs were synthesized by chemical vapor deposition, and their nanocomposites were prepared by melt-mixing with polyvinylidene fluoride (PVDF). In the synthesis of N-CNTs, three catalysts of Co, Fe and Ni, and three temperatures of 650, 750 and 950 °C were employed. The morphology, aspect ratio, synthesis yield, remaining residue, nitrogen content, nitrogen bonding type, and powder conductivity of N-CNTs, and the morphology, polar crystalline phase, and broadband dielectric properties of N-CNT/PVDF nanocomposites were investigated. The results revealed that by proper selection of synthesis catalyst (Fe) and temperature (650 °C and 950 °C), nitrogen doping generated polarizable nanotubes via providing local polarization sites, and resulted in nanocomposites with favorable dielectric properties for charge storage applications at N-CNT loadings as low as 1.0 wt%. As a result, 3.5 wt% (N-CNT)Fe/950°C/PVDF nanocomposites exhibited an insulative behavior with ϵ' = 23.12 and tan δ = 0.05 at 1 kHz, a combination superior to that of PVDF, i.e., ϵ' = 8.4 and tan δ = 0.03 and to those of percolative nanocomposites, e.g., ϵ' = 71.20 and tan δ = 63.20 for 3.5 wt% (N-CNT)Fe/750°C/PVDF. Also, the relationships between the dielectric properties, N-CNT structure, and nanocomposite morphology were identified.enghttps://creativecommons.org/licenses/by-nc-nd/4.0/540Aspect ratioCatalystsChemical bondsChemical vapor depositionDielectric lossesDielectric propertiesDielectric properties of solidsDoping (additives)Fluorine compoundsMorphologyNanocompositesNanotubesNitrogenPermittivityYarnArticle