Magnetic and conducting Fe3O4–cross-linked polyaniline nanoparticles with core–shell structure

Magnetic and conducting Fe3O4–cross-linked polyaniline (CLPANI) nanoparticles with core–shell structure have been prepared in the presence of magnetic fluid in aqueous containing polyethylene glycol as a surfactant. The magnetic properties of the resulting composites showed ferromagnetic behavior, such as high-saturated magnetization (Ms=4.22–19.22 emu/g), and coercive force (Hc=2–8 Oe). The saturated magnetization increased with the increasing of Fe3O4 content. The conductivity of the composites at room temperature depended on the Fe content and doping degree. A structural characterization by elemental analysis, Fourier transform infrared, transmission electron micrograph (TEM) and X-ray diffraction proved that nanometer-sized (about 10 nm) Fe3O4 in the composites was responsible for the ferromagnetic behavior of the composites. The average size of Fe3O4–CLPANI nanocomposites with core–shell structure was about 40 nm, and polydisperse. The results of TG, IR and UV spectra indicated that the Fe3O4 particles could improve the composite thermal stability due to interaction between the Fe3O4 particles and CLPANI polymer backbone.