纳米纤维聚苯胺膜在不锈钢电极表面的生长过程

Growth Process of Nano-fibrous Polyaniline Film on Stainless Steel

研究了脉冲电流法(PGM)聚合苯胺时,纳米纤维聚苯胺(PANI)膜在不锈钢(SS)电极表面的生长过程.用计时电位法和扫描电子显微镜(SEM)表征了聚苯胺生长过程的电化学特征和微观形貌;并通过循环伏安(CV)法研究了苯胺的聚合速率.结果表明,聚苯胺的生长经历了两个阶段,首先是在裸不锈钢电极表面上形成颗粒状聚苯胺,此时聚合电位约为1.10V,经历了30s后,电极表面被一层颗粒状聚苯胺膜所覆盖;在此基础上,聚苯胺以纳米纤维状结构继续生长,当颗粒状聚苯胺被纳米纤维状聚苯胺膜完全覆盖时,聚合电位降至0.75V左右并保持稳定.

The growth of nano-fibrous polyaniline （PANI） film on stainless steel （SS） by pulse galvanostatic method （PGM） in 0.3 mol · L^-1 aniline ＋ 1 mol ·L^-1 HNO3 aqueous solution at 1 mA·cm^-2 was studied. The electrochemical behavior during the polymerization and the morphology of the PANI films with various deposition charges were characterized by chronopotentiogram and scanning electron microscope （SEM）, respectively. Moreover, the rate of aniline electropolymerization was determined by the cyclic voltammetry（CV） technique. The results showed that the polymerization of aniline on SS involved two separate stages. Firstly, polyaniline grew on bare SS electrode and represented granular structure. In this stage, the potential of aniline polymerization was relatively positive （at ca. 1.10 V）. After about 30 s, the surface of the SS electrode was entirely covered by a granular PANI film. Secondly, PANI grew further with nano-fibrous morphology on the surface of the granular PANI film. The polymerization potential maintained ca. 0.75 V when the granular PANI film was entirely covered by the nano-fibrous PANI film.