CC BY-NC-ND 4.0 UnportedArjmand, MohammadChizari, KambizKrause, BeatePötschke, PetraSundararaj, Uttandaraman2023-10-132023-10-132016https://oa.tib.eu/renate/handle/123456789/12480https://doi.org/10.34657/11510Different catalysts including Co, Fe, and Ni were used to synthesize nitrogen-doped carbon nanotubes (N-CNTs) by chemical vapor deposition technique. Synthesized N-CNTs were melt mixed with a polyvinylidene fluoride (PVDF) matrix using a small scale mixer at different concentrations ranging from 0.3 to 3.5 wt%, and then compression molded. The characterization techniques revealed significant differences in the synthesis yield and the morphological and electrical properties of both N-CNTs and nanocomposites depending on the catalyst type. Whereas Co and Fe resulted in yields comparable to industrial multiwalled CNTs, Ni was much less effective. The N-CNT aspect ratio was the highest for Co catalyst, followed by Ni and Fe, whereas nitrogen content was the highest for Ni. Raman spectroscopy revealed lowest defect number and highest N-CNT crystallinity for Fe catalyst. Characterization of N-CNT/PVDF nanocomposites showed better dispersion for N-CNTs based on Co and Fe as compared to Ni, and the following order of electrical conductivity and electromagnetic interference shielding (from high to low): Co > Fe > Ni. The superior electrical properties of (N-CNT)Co nanocomposites were ascribed to a combination of high synthesis yield, high aspect ratio, low nitrogen content and high crystallinity of N-CNTs combined with a good state of N-CNT dispersion.enghttps://creativecommons.org/licenses/by-nc-nd/4.0/540Aspect ratioCarbonCatalystsChemical vapor depositionDoping (additives)Electric conductivityElectric conductivity of solidsElectromagnetic pulseElectromagnetic shieldingElectromagnetic wave interferenceMultiwalled carbon nanotubes (MWCN)NanocompositesNanotubesNickelNitrogenShieldingSignal interferenceYarnArticle