X‐band dielectric properties of hybrid nanocomposites of nitrogen‐doped carbon nanotube/functionalized nanoclay/polyvinylidene fluoride nanocomposite

Abstract This study investigates the effect of functionalized nanoclay on dielectric properties in the X‐band (8.2‐12.4 GHz) of synthesized nitrogen‐doped carbon nanotube (N‐CNT)/nanoclay/polyvinylidene fluoride (PVDF) nanocomposites prepared via melt‐mixing. Montmorillonite nanoclay was functionalized by an aminosilane coupling agent, making the nanoclay more compatible with the organic polymer. N‐CNT was synthesized employing a chemical vapor deposition technique. Transmission electron microscopy and optical microscopy were used to assess the morphology of nanocomposites. The incorporation of nanoclay improved the dielectric properties, that is, dissipation factor of N‐CNT/PVDF nanocomposites. For instance, incorporation of 0.5 wt% nanoclay into N‐CNT/PVDF nanocomposite at 1.0 wt% N‐CNT loading resulted in 61% reduction in the dissipation factor (from 0.18 ± 0.01 to 0.07 ± 0.01). The percolation threshold increased from 0.3 to 1.0 wt% of N‐CNT by incorporation of 0.5 wt% nanoclay, which expanded the percolation region. In addition, incorporation of 0.5 wt% nanoclay reduced agglomeration area ratio of 1.0 wt% N‐CNT/PVDF nanocomposite by 57%. Rheological results indicated collapse of N‐CNT networks upon addition of nanoclay to the N‐CNT/PVDF nanocomposite, which confirmed the dielectric results. Nitrogen heteroatoms (scattering centers) and functionalized nanoclay were responsible for reducing the dissipation factor.