Fabrication and study of multifunctional properties of PANI–WO₃ conducting paper

Flexible conducting composites of polyaniline tungsten trioxide (PANI–WO₃) were effectively created using in-situ oxidative polymerization and applied to Whatman filter paper substrates. The study systematically examined pure polyaniline (PANI) and PANI–WO₃ composites with 5, 10, and 15 wt% WO₃ for their structural, optical, dielectric, electrical, and antimicrobial characteristics. XRD and FTIR analyses verified the successful integration of WO₃ nanoparticles into the PANI matrix, while SEM images showed notable morphological changes due to composite formation. UV–Visible analysis revealed a decrease in the optical band gap from 2.65 eV for pure WO₃ to 2.28, 2.45, and 1.89 eV for the PW5, PW10, and PW15 composites, respectively, indicating improved electronic interaction between PANI and WO₃. Dielectric studies demonstrated a strong frequency-dependent behavior, with the PW10 composite showing the highest dielectric constant (K′ = 16.45) at 50.06 Hz, suggesting enhanced interfacial polarization and charge storage capacity. AC conductivity was assessed across a broad frequency spectrum at ambient temperature and under various thermal conditions up to 353 K. The conductivity increased with frequency, peaking at 1.07 × 10⁻⁵ S cm⁻¹ for the PW5 composite. Impedance analysis indicated non-Debye relaxation behavior and enhanced charge transport properties within the composite system. Antimicrobial tests showed notable effectiveness against Escherichia coli, Staphylococcus aureus, and Candida albicans, with the PW10 composite achieving the largest inhibition zones of 12, 14, and 14 mm, respectively. PW10 stood out among all compositions for its well-rounded dielectric, electrical, and antimicrobial properties, underscoring its suitability for applications in flexible sensing, electronics, and antimicrobial fields.