In Situ Synthesis of Polypyrrole-γ-Fe2O3‑Fly Ash Nanocomposites for Protection against EMI Pollution

The present paper reports utilization of an industrial byproduct fly ash for potential application by designing nanostick shaped polypyrrole composites decorated with γ-Fe2O3 and fly ash particles via in situ emulsion polymerization. The structural, magnetic, and electromagnetic shielding properties of the composites with varying loading of γ-Fe2O3 and fly ash particles have been investigated. The result indicates that these properties can be optimized by modulating the concentration of the constituents in a polymer matrix. Polypyrrole-γ-Fe2O3-fly ash nanocomposites have a superparamagnetic nature with an M s value of 13.55 emu/g, electrical conductivity of the order of 10–2 S/cm, and a maximum SE due to absorption (SEA(max)) being ca. 17.4 dB. The overall shielding effectiveness (SE = SEA + SER) up to 25.5 dB (∼99.7% attenuation) has been recorded for polypyrrole nanocomposites having pyrrole, γ-Fe2O3, and fly ash in a 1:1:0.5 wt. ratio in the frequency range of 12.4–18 GHz (Ku-band).