Improved conductivity and electrical properties of polyaniline in the presence of rare-earth cations and magnetic field

The influence of rare-earth cations on the preparation and properties of polyaniline (PANI) was investigated in the presence of a magnetic field. It was found that the addition of rare-earth cations can greatly increase the polymerization rate of PANI in the following order: Tb3+ > Nd3+ > Ce3+. When a parallel magnetic field (B-p) was imposed with respect to the electrode surface, the maximum polymerization rate was obtained at B-p = 0.5 T. Whereas, in a perpendicular magnetic field (B-s), the rate was accelerated as the magnetic flux density rose. The conductivity of PANI/Tb3+/B-p = 0.7 T film was 115.4 S cm(-1) which, as expected, is higher by about an order of magnitude as compared to the parent PANI film without the effects of rare-earth cations and magnetic field. Meanwhile, the X-ray diffraction patterns and electrochemical impedance spectroscopy indicated an increase of crystallinity and a more-ordered arrangement of the polymer chains with a concurrent increase in the capacitance, and a decrease in the charge transfer resistance and the ohmic resistance in the presence of rare-earth cations and magnetic field.