Ferromagnetic polyaniline/TiO <inf>2</inf> nanocomposites

Abstract

Novel ferromagnetic semiconducting polyaniline PANI/TiO 2 nanocomposites were synthesized by the oxidative polymerization of aniline with ammonium peroxydisulfate in an aqueous medium, in the presence of colloidal TiO 2 nanoparticles (d ∼ 4.5 nm), without added acid. The morphological, magnetic, structural, and optical properties of the PANI/TiO 2 nanocomposites prepared at initial aniline/TiO 2 mole ratios 80, 40, and 20 were studied by scanning electron microscopy, superconducting quantum interference device, X-ray powder diffraction, FTIR, Raman, and UV-Vis spectroscopies. The emeraldine salt form of linear PANI chains as well as the presence of phenazine units, branched PANI chains, and anatase crystalline structure of TiO 2 in PANI/TiO 2 nanocomposites was confirmed by FTIR and Raman spectroscopies. The electrical conductivity of synthesized composites was ∼10 -3 S cm -1. The room temperature ferromagnetic response with coercive field of H c ∼ 300 Oe and the remanent magnetization of M r ∼ 4.35 × 10 -4 emu/g was detected in all investigated PANI/TiO 2 nanocomposites. © 2012 Society of Plastics Engineers.