Electromagnetic interference shielding behaviors of in-situ polymerized ferrite-polyaniline nano-composites and ferrite-polyaniline deposited fabrics in X-band frequency range

Ferrite-PANI composites were prepared via in-situ polymerization. Nano particles of Ni1-xZnxFe2O4 (0.0 <= x <= 0.4) have been prepared by the sol-gel technique. Composites were made by in-situ polymerization of aniline monomer in the presence of ferrite nanoparticles. X-ray diffraction analysis of ferrite nanoparticles confirmed the existence of spinel nature with phase formation at very low annealing temperature. The presence of both the phases in composites was confirmed by XRD analysis. The average crystallite size was estimated in 20-30 nm range using Rietveld refinement. Magnetic hysteresis loops recorded at room temperature for ferrites as well as their composites showed that the magnetization first increased up to Zn = 0.3 and then started decreasing with increasing Zn concentration. The electromagnetic interference shielding behavior has been investigated for composite samples in the X-band frequency region. With the amalgamation of ferrite nanoparticles (50 wt%) in the PANI, a very high shielding effectiveness of 60 dB has been attained which indicates more than 99.9% of incident EM radiation get attenuated by the composites having high permeability and magnetic electric losses. Magnetic and dielectric coated fabrics were prepared during in-situ polymerization of the composites. Ferrite-PANI coated fabrics of thickness 0.30 mm demonstrated high shielding effectiveness of 40-48 dB. Hence, high performance electromagnetic interference shielding ferrite-polyaniline nano composites and coated fabrics have been synthesized successfully for applications. (C) 2020 Elsevier B.V. All rights reserved.