PANI is difficult to process because of its poor dispensability and solubility. A novel approach for one-step synthesis of bulk quantities of nano-polyaniline using H2O2 and FeCl2 as oxidant and inorganic acid as dopant was developed. The results indicated that the dispensability of the PANI in distilled water and butanol was excellent because of the effective stabilization of the H2O2/FeCl2 system. The coated steel with the PANI coating exhibited significant smooth surface and higher adhesion. It is also found that the PANI coating offered the best corrosion resistance and the lowest corrosion current in 3.5 wt% NaCl solution. The possible mechanism of PANI coating corrosion protection was the effect of pin-hole passivation.
More detailed information can be found in: W. P. Hou, Y. Liu, Z. Y. Ge and W. Y. Zhao, Comparison study on anticorrosion performances of the epoxy coatings with two different nano-polyanilines for Q235 steel, Materials and Corrosion 2013, 64, 960.