Anticorrosive polyaniline-coated copper oxide (PANI/CuO) nanocomposites with tunable electrical properties for broadband electromagnetic interference shielding

This paper presents the electromagnetic interference (EMI) shielding and anti-corrosion characteristics of polyaniline (PANI) coated copper oxide (CuO) nanocomposites. PANI/CuO composites were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energydispersive X-ray spectroscopy, transmission electron microscopy (TEM), Raman spectroscopy, and thermogravimetry analysis (TGA). Frequency-dependent (AC) conductivity, and dielectric attributes of the composites were analyzed at room temperature in the frequency range of 10 Hz-1 MHz. The AC conductivity and dielectric properties showed tunability with varying concentrations (weight percentage) of CuO particles in PANI. The EMI shielding measurements were carried out in the Ku band (12-18 GHz) frequency range of practical relevance. The results show that, PANI/CuO composites exhibited high electromagnetic interference shielding efficiency due to high surface area and the presence of heterogeneous phase components in their moieties. The anticorrosion behavior of PANI/CuO on mild steel (MS) surface in 5 M HCl corrosive solution was performed by using the atomic absorption spectroscopy (AAS), Tafel plot, and AC impedance spectroscopy techniques. Surfacestudies were performed by using scanning electron microscopy technique. AAS results indicated that, MS corrosion mitigating efficiency of PANI/CuO nanocomposite is concentration-dependent and protection efficiency is improved with a boost in the PANI/CuO nanocomposite amount. Tafel plots confirmed that, PANI/CuO composite acts as an anodic type of inhibition system. The effect of the protective barrier invisible layer at the surface of the MS was analyzed by Nyquist plot studies and SEM topography showed the mitigation effect of the PANI/CuO system on the MS surface. Finally, our results show that, anticorrosive PANI/CuO can be a good choice for broadband microwave attenuation and EMI shielding applications.