The nucleation and growth mechanism of polyaniline

The nucleation and growth kinetics of electrochemical formation of polyaniline (PAN) have been studied by potentiostatic step techniques. The initial parts of the current transients obtained at different media are explained by means of the theory for progressive and instantaneous nucleation and growth. The experimental results have shown that the formation of the PAN film occures via progressive nucleation following a three-dimentional (3-D) hemispherical growth model with diffusion controlled in the solution of 0.5 mol . L(-1) An/0.5 mol . L(-1) H2SO4. But in the media of HClO4, the electrodeposition of PAN proceeds favourably through two-dimensional (2-D) nucleation and growth under the kinetic controlled. Multinuclear growth of 3-D nuclei may form a grain porous PAN film. While the lateral growth of 2-D nuclei may be expected to have more uniform and compact arrangement of polymer chains.