Aniline dimer–COOH assisted preparation of well-dispersed polyaniline–Fe3O4nanoparticles

Polyaniline (PANI)–Fe 3 O 4 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–Fe 3 O 4 nanoparticles. The structure of Fe 3 O 4 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–Fe 3 O 4 nanocomposite showed that the Fe 3 O 4 nanoparticles were well dispersed in PANI matrices. The PANI–Fe 3 O 4 composite was characterized by means of FTIR, XPS and XRD analyses. The PANI–Fe 3 O 4 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 (μ c = 0).