Morphology of poly (N-methylaniline) electrodeposited from different acid solutions

The electropolymerization of N-methylanilite was accomplished in five different acid solutions: HCl, HNO 3 , H 2 SO 4 , HBF 4 and HClO 4 . Although the electrical conductivity of each obtained poly(N-methylaniline) (PNMA) was on about the same order, the nucleation process and their morphologies were quite different. For the electropolymerization in the HCl, HNO 3 and H 2 SO 4 solutions, the 1D nucleation growth of PNMA took place resulting in a network structure of fibrils (for HCl) or irregular granular structures (for HNO, and H 2 SO 4 ). It was suggested that the PNMA growth in the HBF 4 and HClO 4 solutions was caused by the precipitation of the oligomer-coupling polymers. It was interesting to find that the surface of the PNMA obtained from the HClO 4 and HBF 4 solutions had spherical microparticles on the compact PNMA layer, whose diameters were in the range of 2-8 μm.