Fe3O4@ Au/polyaniline multifunctional nanocomposites:: their preparation and optical, electrical and magnetic properties

Fe3O4@ Au/polyaniline (PANI) nanocomposites were fabricated by in situ polymerization in the presence of mercaptocarboxylic acid. The mercaptocarboxylic acid was used to introduce hydrogen bonding and/or electrostatic interaction; it acts as a template in the formation of Fe3O4@ Au/PANI nanorods. The morphology and structure of the resulting nanocomposites were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, x-ray diffraction and x-ray energy dispersion spectroscopy (EDS). It was found that the nanocomposites were rod-like with an average diameter of 153 nm, and they exhibited a core-shell structure. A UV-visible spectrometer, semiconductor parameter analyzer and vibrating sample magnetometer (VSM) were used to characterize the optical, electrical and magnetic properties of the Fe3O4@ Au/PANI nanocomposites. It was interesting to find that these properties are dependent on the molar ratio of Au to Fe3O4 when the molar ratio of Fe3O4@ Au to PANI is fixed. The magnetic property of the Fe3O4@ Au/PANI nanocomposite is very close to superparamagnetic behavior.