Synthesis of electrically conductive and superparamagnetic monodispersed iron oxide-conjugated polymer composite nanoparticles by in situ chemical oxidative polymerization

Core–shell nanocomposites composed of iron oxide (Fe3O4) nanoparticles and conjugated polymer, poly(3, 4-ethylenedioxythiophene) (PEDOT), were successfully synthesized from a simple and inexpensive in situ chemical oxidative polymerization of EDOT with Fe3O4 nanoparticles in the micellar solution of lignosulfonic acid (LSA) which serves as both a surfactant and a dopant. These nanocomposites (Fe3O4–PEDOT) were subsequently characterized for morphological, crystalline, structural, electrical and magnetic properties by high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), four-probe meter and superconductor quantum interference device (SQUID), respectively. Results show that the nanocomposites have a spherical core–shell shape, are ∼10 nm in size and are superparamagnetic with good magnetic saturation and good electrical conductivities. Existence of Fe3O4 in the nanocomposites was confirmed by using Energy dispersive X-ray photoelectron spectroscopy (EDAX) and X-ray photoelectron microscopy (XPS). We also investigated a possible formation mechanism of the core–shell nanocomposites, and the effect of Fe3O4 nanoparticles on the electro-magnetic properties of the nanocomposites. Such novel conducting and superparamagnetic composite nanomaterials can be applied to sensors, magnetic data storage, electro-magnetic resonance wave absorption, etc.

Graphical abstractConducting and superparamagnetic monodispersed Fe3O4–poly(3, 4-ethylenedioxythiophene) core–shell composite nanoparticles with the size about 15 nm, were synthesized via an in situ chemical oxidative polymerization in the micellar solution of lignosulfonic acid (LSA).Figure optionsDownload full-size imageDownload as PowerPoint slide