EMI shielding study of PVC-PT-Ag/ZnS nanocomposites in microwave region

Chemical oxidative polymerization and hydrothermal methods were employed to synthesize polythiophene (PT) and silver-doped zinc sulfide (Ag/ZnS) nanoparticles for electromagnetic interference (EMI) shielding applications. Composite films based on PVC were fabricated by incorporating these nanoparticles, both Ag/ZnS and PT-Ag/ZnS. Initially, X-ray diffraction and zetasizer technology were utilized to analyze the crystal structure and particle size of these nanoparticles. Subsequently, the nanocomposite films were assessed for various properties, including electrical conductivity and transmittance in the near-infrared wavelength range of 200–800 nm, as well as their effectiveness in shielding electromagnetic interference in the microwave frequency range of 0.1–20 GHz. The aforementioned features were investigated using DC conductivity, vector network analysis, and NIR spectroscopy. It was discovered that both conductance and shielding effectiveness increased to 0.029 S/cm and 54 dB, respectively, as the nanoparticle density increased. At 20 wt% PT-Ag/ZnS, the maximum attenuation value within the 0.1–20 GHz frequency band reached 54 dB, with transmittance below 0.5 %.