Unique properties of polyaniline in the presence of applied magnetic field and ferric chloride

Fe-contained polyaniline (abbreviated as PANI-Fe) was prepared by chemical oxidation of aniline with ammonium peroxydisulfate oxidant in 0.5 mol dm(-3) HCl and an adequate content of FeCl3 center dot 6H(2)O solution in the presence of an applied magnetic field at room temperature. The X-ray photoelectron spectroscopy (XPS) and UV-vis and FTIR spectra suggest that there is an interaction between FeCl3 and PANI chains, but PANI-Fe backbone is essentially identical with that of parent polyaniline. The electron paramagnetic resonance (EPR) spectrum shows that there were unpaired electrons in PANI-Fe synthesized in the presence of an applied magnetic field, the spin density and the conductivity of which are 7.308 x 10(20) spins g(-1) and 0.891 S cm(-1), respectively. The plot of magnetization (M) vs. the applied magnetic field (H) displays that the PANI-Fe possesses soft ferromagnetic behavior at room temperature. The results of cyclic voltammogram show that the PANI-Fe film is of excellent electrochemical activity. (C) 2010 Elsevier B.V. All rights reserved.