聚苯胺的成核及生长机理

The Nucleation and Growth Mechanism of Polyaniline

本文通过恒电位阶跃法研究了聚苯胺在不同介质中的成核与膜的生长过程动力学.结果表明,在硫酸介质中,成核过程为扩散控制下的三维连续成核,得到疏松、多孔的膜;而在高氨酸介质中,成核则是电化学动力学控制下的二维成核过程.在高电位时(E>1.02V,vs.SCE)为二维连续成核过程,而在较低的电位时,主要表现为二维瞬时成核,膜层呈网状且致密.

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 0.5mol ·L-1An/0.5mol·L-1H2SO4. 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.