Dielectric and electromagnetic interference shielding properties of carbon black nanoparticles reinforced PVA/PEG blend nanocomposite films

Polyvinyl alcohol (PVA)/polyethylene glycol (PEG) blend nanocomposite films reinforced with various loadings of carbon black nanoparticles (CBNPs) were synthesized via a solution casting approach. The structural properties of PVA/PEG/CBNPs nanocomposites were investigated using Fourier-transform infrared (FTIR) spectroscopy, indicating the strong interaction of CBNPs with the polymer blend. The thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) results respectively confirmed the enhanced thermal stability and the variation in the melting temperature with the addition of CBNPs in polymer blend . The dielectric measurements of nanocomposite films were carried out over a frequency range from 50 Hz–20 MHz at a varied temperature range from 40 °C–150 °C using impedance analyzer . The maximum dielectric constant for neat PVA was observed to be about 21.4 at 50 Hz and 150 °C. For PVA/PEG/CBNPs nanocomposites having higher loading of CBNPs (25 wt%) the maximum value of dielectric constant was found to be ε = 375.1 at 50 Hz, 150 °C. The dielectric properties increased with the addition of CBNPs which validates a significant control on percolation threshold attributing to the well-dispersed CBNPs in the polymer blend. The electromagnetic interference (EMI) shielding effectiveness (SE) was improved from 0.1 dB to 10.6 dB with the addition of CBNPs in the PVA/PEG blend. The improved EMI SE and dielectric performance of these nanocomposites suggest CBNPs as excellent nanofillers for the development of flexible, lightweight and low-cost material for electronic applications.