Electrical Conductivity and EMI Shielding Efficiency of PPY-PVA-Ni Nanocomposite Films

Conducting polymers with metal/metal oxide nanocomposites have recently attracted more attention from both the scientific sector and industry, with a focus on electrical and electromagnetic interference (EMI) shielding applications. Free-standing PPY-PVA/Ni (1, 2, 3, 4, and 5) ternary composite films were chemically synthesized by in situ chemical oxidative polymerization of pyrrole and polyvinyl alcohol (PVA, binder matrix) using ammonium persulfate as the oxidizing agent and coated with different concentrations (0.01, 0.02, 0.03, 0.04, and 0.05 M) of Ni⁺ ions using Adathoda vasica leaf extract as a reducing agent. The effect of PPY-PVA/Ni nanocomposites on the electrical and EMI shielding properties of nanocomposites was studied. The crystal structure of the dopant (Ni nanoparticles), thermal degradation and morphology of these composites were characterized by XRD, FESEM and TG analysis. The maximum electrical conductivity (4.2 × 10^–4 S/cm) was also achieved by doping PPY-PVA binary composites with 0.01 M Ni⁺ ions to form PPY-PVA/Ni-1 ternary nanocomposites. This significant increase in electrical conductivity achieves an EMI shielding effect of up to ~16.5 dB in the frequency range from 2.1 to 3 GHz (S-Band). An increase in electrical conductivity and EMI shielding for composites with hybrid fillers (PPY-PVA/Ni) demonstrates the synergistic benefits of such fillers when used together. Hence, these conducting polymers with metal/metal oxide nanocomposites could have the potential to be advantageous materials for technological applications.