Ferromagnetic Conductive Polyaniline - Synthesis And Characterization Of Cobalt Or Iron

Ferromagnetic polyaniline is synthesized in a solution containing 0.1 mol dm-3 aniline, 0.5 mol dm-3 HCl and an adequate content of metallic ions (CoCl2 or FeCl3) at room temperature, using peroxydisulphate as an oxidant (Polyaniline doped with CoCl2 abbreviated as PANI-Co and polyaniline doped with FeCl3 abbreviated as PANI-Fe). Magnetic Properties of PANI-Co and PANI-Fe were measured by Vibrating Sample Magnetometer (VSM), the magnetization (M) versus the applied magnetic field (H) curves showed that PANI-Co and PANI-Fe were soft ferromagnetic properties at room temperature. The saturation magnetization (Ms) of PANI-Co and PANI-Fe were 4.02 emu g-1 (electromagnetic unit per gram) and 5.7 emu g-1, respectively. The conductivities of PANI-Co and PANI-Fe were in the magnitude order of 10-1~10-2 S cm-1. The results of electron paramagnetic resonance (EPR) spectra indicated that the spin density of PANI-Co was 6.01×1019 spins g-1; and the spin density of PANI-Fe was 2.35×1020 spins g-1. The UV-vis and FTIR spectra showed that there was the strong coordination between Co2+ or Fe3+ and N atoms in the PANI chains, but the backbone chains of PANI-Co and PANI-Fe were hardly changed compared with that of PANI, which is confirmed by TGA of PANI-Co and PANI-Fe. According to the results of FAAS, the Co (Fe) content in PANI-Co (PANI-Fe) was about 0.5%, which may be explained by Peauson's theory of Hard and Soft acids and bases (HSAB). According to XRD the crystallinities of PANI-Co and PANI-Fe were almost the same as the crystallinity of PANI. The results of the cyclic voltammograms indicated that the ferromagnetic PANI-Co and PANI-Fe films were of excellent electrochemical activity.PANI-Co and PANI-Fe were synthesized using peroxydisulphate as an oxidant in a solution containing 0.1 mol dm-3 aniline, 0.5 mol dm-3 HCl and an adequate content of metallic ions (CoCl2 or FeCl3) in the applied magnetic field. The conductivities of the resulting products were in the magnitude order of 10-1~10-2 S cm-1. The EPR spectra displayed that there were unpaired electrons in PANI-Co and PANI-Fe synthesized in the applied magnetic field, the spin density of which were improved (6.903×1019 spins g-1 and 7.308×1020 spins g-1) compared with PANI-Co and PANI-Fe synthesized without magnetic field; The curve of magnetization (M) versus the applied magnetic field (H) showed that PANI-Co and PANI-Fe synthesized under magnetic field had soft ferromagnetic property at room temperature. The saturation magnetization (Ms) of PANI-Co and PANI-Fe synthesized under magnetic field were 6.6 emu g-1 and 6.9 emu g-1 respectively, the saturation magnetization of which increased compared with those of PANI-Co and PANI-Fe in the absence of the applied magnetic field. The UV-vis and FTIR spectra implied that there was the strong coordination between Co2+ or Fe3+ and N atoms in the PANI chains, but the structure of backbone chains of PANI-Co and PANI-Fe with magnetic field hardly changed compared with that of PANI. According to the results of FAAS, the Co (Fe) content in PANI-Co (PANI-Fe) was about 0.5%, which may be explained by Peauson's theory of Hard and Soft acids and bases (HSAB). According to XRD the crystallinities of PANI-Co and PANI-Fe in the applied magnetic field were almost the same as the crystallinity of PANI. The metal contents (Co and Fe) of the resulting products were a litter higher than those of PANI-Co and PANI-Fe without magnetic field. The results of the cyclic voltammograms indicated that the ferromagnetic PANI-Co and PANI-Fe films with magnetic field were of more excellent electrochemical activity than those without magnetic field.