Polyaniline/V2O5 composites for anticorrosion and electromagnetic interference shielding

Abstract

Conducting polyaniline (PANI)/vanadium pentoxide (V2O5) nanocomposites have been synthesized by interfacial polymerization technique. The composites have been characterized by X-ray diffraction (XRD), Fourier transforms infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The electrical conductivity (σac) and dielectric measurements have been carried out in the frequency range of 50 Hz to 1 MHz at ordinary lab temperature. The dielectric constant of the composites has been increased to a very high-value of 3.75 × 105 at lower frequency (1 kHz) for 15 wt% concentration of V2O5 in PANI. The electromagnetic shielding behavior of the composites has been investigated in the frequency range 12–18 GHz (Ku-band) of the microwave region. The shielding results demonstrate the synergistic effect of the composite phases with average shielding effectiveness (SE) values in the range of ~17 to 19 dB (<99% electromagnetic energy attenuation). To explore the multifunctional application potential of the composites, surface protection of PANI/V2O5 on mild steel (MS) in 5 M HCl acid solution has been screened by atomic absorption spectroscopy (AAS), Tafel curves, ac impedance, and SEM. AAS and SEM reveal adsorption dominated high inhibition property of these nanocomposites of the order of 91.397%. The potentiodynamic polarization scan indicates both the cathodic and anodic dissolution inhibition role of PANI/V2O5. Nyquist plots greatly sustain the improvement of charge transfer resistance with PANI/V2O5 in the corrosive (5 M HCl) solution. The results show that these nanocomposites could be optimized for diverse applications in corrosion inhibition and stealth technology.