Electromagnetic interference shielding effectiveness of compression molded carbon nanofiber‐reinforced polyvinylidene difluoride film

Abstract In this study, vapor grown carbon nanofiber (VGCNF) reinforced polyvinylidene difluoride (PVDF) composites were developed. Composites were fabricated by high shear mixing using a Banbury type mixer. The material was then subjected to compression molding resulting in films with an average thickness of 0.82 mm. The developed films were subjected to physico‐thermal, and electrical characterization including analysis of the shielding effectiveness (SE) of electromagnetic interference (EMI). Morphological analysis was conducted by scanning electron microscopy and characterization complemented with Fourier transform infrared spectroscopic and X‐ray diffraction analyses. The thermal properties were studied by differential scanning calorimetry and thermogravimetric analysis, which revealed the influence of carbon nanofibers on thermal stability and phase transitions. The electrical conductivity for in‐plane and through‐plane was gradually enhanced by increasing the concentration of VGCF loading; a percolation threshold was initiated at 5 wt% loadings. In plane and through plane resistivity decreased from 10¹¹ Ω‐cm to 10³ Ω‐cm and 10² Ω‐cm, respectively. An in‐depth EMI SE study was conducted depicting the influence of VGCNFs on skin depth, EMI power coefficients for reflection, absorption and transmission, and EMI SE for reflection, absorption, and total. The total SE of the developed nanocomposite films was observed to range between 6.6–16.4 dB in a frequency range of 30 kHz to 1.5 GHz. This study presents the processing‐structure–property relationships for lightweight and flexible NC films with enhanced electrical conductivity.