Preparation of multi-core/single-shell OA-Fe3O4/PANI bifunctional nanoparticles via miniemulsion polymerization

Conductive and magnetic oleic acid modified Fe3O4 (OA-Fe3O4)/polyaniline nanoparticles with multi-core/single-shell morphology had been synthesized via a novel and facile in situ miniemulsion polymerization approach. The dominant polymerization loci of aniline at the surface of Fe3O4 particles were ensured owing to the unique monomer droplet nucleation mechanism of miniemulsion polymerization. Modification of Fe3O4 by oleic acid (OA) played an important role in the coating process, which not only decreased the agglomeration degree of Fe3O4, but also favored the generation of hydrogen bonding between Fe3O4 and PANI thus enhance their interfacial combination. The conductivity and saturated magnetization of the nanocomposites could be tuned by the addition amount of OA-Fe3O4. The present method can be extended to fabricate other magnetic/conductive core/shell composites, and these unique core/shell spherical materials could find applications in catalyst supports or biomedical areas.