Synthesis of conducting ferromagnetic nanocomposite with improved microwave absorption properties

Abstract

The present paper reports the synthesis of polyaromatic amine–ferromagnetic composite with nanosize TiO 2 (∼70–90 nm) and γ-Fe 2O 3 (∼10–15 nm) particles via in situ emulsion polymerization. Magnetic and conductivity studies demonstrate that the conducting ferromagnetic composite possesses saturation magnetization ( M S ) value of 26.9 emu g −1 and conductivity of the order of 0.46 S cm −1, which are measured by vibrating sample magnetometer and four-probe technique, respectively. It is observed that the presence of the nanosized γ-Fe 2O 3 in the polyaniline–TiO 2 matrix affects the electromagnetic shielding property of the composite. Polyaniline–TiO 2–γ-Fe 2O 3 nanocomposite has shown better shielding effectiveness due to absorption (SE A ∼ 45 dB) than the polyaniline-γ-Fe 2O 3 (SE A ∼ 8.8 dB) and polyaniline–TiO 2 (SE A ∼ 22.4 dB) nanocomposite. The polymer composites were further characterized by high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) technique.