Fabrication and characteristic of conductive and ferromagnetic hollow composite microcapsules

The fabrication of conductive and ferromagnetic hollow composite microcapsules with polypyrrole (PPy) shell and Fe₃O₄ inner-wall was successfully accomplished via a sequential processes of electrostatic attraction between negatively charged polystyrene (PS) latex and Fe₃O₄ nanoparticles, the polymerization of pyrrole and the dissolution of PS core. The morphology of the hollow composite microcapsules was testified by TEM and XRD. The hollow microcapsules possessed a conductivity of 10^− 2 S/cm, and their ferromagnetic property was attributed to the presence of magnetic Fe₃O₄ nanoparticles on the inner-wall. The improved thermal stability of the hollow microcapsules could be interpreted due to the interaction between Fe₃O₄ nanoparticles and PPy chains.