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 gamma-Fe2O3 and fly ash particles via in situ emulsion polymerization. The structural, magnetic, and electromagnetic shielding properties of the composites with varying loading of gamma-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-gamma-Fe2O3-fly ash nanocomposites have a superparamagnetic nature with an M-s value of 1335 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 (similar to 99.7% attenuation) has been recorded for polypyrrole nanocomposites having pyrrole, gamma-Fe2O3, and fly ash in a 1:1:0.5 wt. ratio in the frequency range of 12.4-18 GHz (Ku-band).