Stabilization of polyaniline by the incorporation of magnetite nanoparticles

► Fe3O4 nanoparticles can enhance the oxidation stability of polyaniline. ► Magnetite had a strong redox effect on the electronic properties of the PANi. ► The nanoparticles favored the Emeraldine phase under air. ► The bipolaronic states of PANi could be dramatically reduced by magnetite.