Electrical Conductivity, Dielectric Behavior and EMI Shielding Effectiveness of Polyaniline-Yttrium Oxide Composites

Abstract

Polyaniline-yttrium trioxide (PAni-Y 2 O 3 ) composites were synthesized by the in-situ polymerization of aniline in the presence of Y 2 O 3 . The composite formation and structural changes in these composites were investigated by X-ray diffraction (XRD), Fourier transform infra red spectroscopy (FTIR), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The direct current (DC) electrical conductivity of the order of 0.51 × 10 −2 S cm −1 -0.283 S cm −1 in the temperature range 300 K-473 K indicates semiconducting behavior of the composites. Room temperature AC conductivity and dielectric response of the composites were studied in the frequency range of 10 Hz to 1 MHz. The variation of AC conductivity with frequency obeyed the power law, which decreased with increasing weight percentage (wt %) of Y 2 O 3 . Studies on dielectric properties shows the relaxation contribution coupled by electrode polarization effect. The dielectric constant and dielectric loss in these composites depend on the content of Y 2 O 3 with a percolation threshold at 20 wt % of Y 2 O 3 in PAni. Electromagnetic interference shielding effectiveness (EMI SE) of the composites in the frequency range 100 Hz to 2 GHz was in the practically useful range of -12.2 dB to -17.2 dB. The observed electrical and shielding properties were attributed to the interaction of Y 2 O 3 particles with the PAni molecular chains.

Effect of Coral‐Shaped Yttrium Iron Garnet Particles on the EMI Shielding Behaviour of Yttrium Iron Garnet‐Polyaniline‐Wax Composites

“…Using non‐magnetic and electrically insulating fly‐ash filler particles, Singh et al, observed an SE value of ∼ ‐32 dB (for 33 wt% PANI and 67 wt% fly‐ash). Furthermore, Faisal et al observed the effect of percolation of Y 2 O 3 (dielectric) particles in PANI‐matrix. They found that, at the percolation threshold (20 wt % of Y 2 O 3 ), the dielectric constant and dielectric loss are maximum.…”

Thermomechanically stable dielectric composites based on poly(ether ketone) and BaTiO3 with improved electromagnetic shielding properties in X‐band

“…Although there are no studies on EMI shielding properties of dielectric polymer composites (PEK/BT composites) but lot of research has been carried out to understand EMI shielding performance of conducting polymer composites (CPCs). Faisal and Khasim studied the effect of different inorganic oxide fillers like yttrium oxide (Y 2 O 3 ), stannous oxide (SnO), antimony oxide (Sb 2 O 3 ) on EMI shielding behavior of polyaniline. EMISE of PAni/Y 2 O 3 composites in the frequency range 100 Hz to 2 GHz was in the range of −12.2 to −17.2 dB with highest value of ∼–17 dB at 20 wt % loading which is sufficient for many practical applications.…”

Influence of Nickel Layer on Electromagnetic Interference Shielding Effectiveness of CuS‐Polyacrylonitrile Fibers

“…Furthermore, studies related to the development of electromagnetic shielding materials have become increasingly popular. [8][9][10][11][12][13] EMI shielding is concerned with protecting devices or humans from electromagnetic waves by reducing the harmful waves present around the protection targets. For this purpose, either the unnecessary electromagnetic waves are shielded, or new circuits are formed using magnetic bodies or conductors.…”