Dielectric, AC conductivity and electromagnetic interference shielding behavior of graphite oxide/polyvinylpyrrolidone composites

Graphite oxide (GrO) was prepared using graphite powder by Hummers technique. GrO was characterized by X-ray diffraction analysis and the scanning electron microscopy analysis. Frequency dependence of the dielectric constant (ε′), a.c. conductivity (σac) and electromagnetic interference (EMI) shielding effectiveness (SE) studies have been carried out on the pure polyvinylpyrrolidone (PVP) and GrO/PVP composites. Addition of GrO into PVP polymer matrix is found to enhance the ε′, σac and SE. The ε′ of GrO/PVP composites was found to reduce with an increase in the frequency. The σac of GrO/PVP composites was enhanced with an increase in the frequency. Highest value 46.02 dB of EMI SE at 50 Hz was obtained in the 50 Hz–5 MHz frequency range. The SE of GrO/PVP composites was found to reduce with an increase in the frequency. The GrO/PVP composites were proven to be a promising highly efficient lightweight substance for the absorbing of EM waves at low frequencies.