Aniline dimer-COOH assisted preparation of well-dispersed polyaniline-Fe3O4 nanoparticles

Polyaniline (PANI)-Fe3O4 nanoparticles were obtained using a novel method: aniline dimer-COOH assisted polymerization. The synthetic strategy involved two steps: first, the composite of magnetic nanoparticles modified with aniline dimer-COOH was synthesized by a chemical precipitation method. Then aniline monomer and oxidant were added to create PANI-Fe3O4 nanoparticles. The structure of Fe3O4 nanoparticles capped with aniline dimer-COOH was characterized by Fourier transform infrared, ultraviolet-visible, x-ray photoelectron spectroscopy and x-ray diffraction analyses. Transmission electron microscope images of the PANI-Fe3O4 nanocomposite showed that the Fe3O4 nanoparticles were well dispersed in PANI matrices. The PANI-Fe3O4 composite was characterized by means of FTIR, XPS and XRD analyses. The PANI-Fe3O4 nanoparticles were found to be superparamagnetic. The hysteresis loop at room temperature showed high saturated magnetization (M-s = 21 emu g(-1)) and a low coercive force (mu(c) = 0).