Nanostructures of polyaniline composites containing nano-magnet

With an average diameter of 80–100 nm, nanostructures (nanorods or nanotubes) of polyaniline (PANI) composites containing Fe3O4 nanoparticles (d≈10 nm) were prepared by a template-free method in the presence of β-naphthalene sulfonic acid (NSA) as a dopant. PANI–NSA/Fe3O4 nanostructures exhibited a superparamagnetic behavior (i.e. no hysteresis loop) and their conductivity was around 10−2 S/cm. However, it was found that the electrical and magnetic properties of PANI–NSA/Fe3O4 nanostructures could be adjusted by changing the content of Fe3O4 nanoparticles in the composites. A template-like model was proposed to interpret the formation of the nanostructures.