化学学报 ›› 2008, Vol. 66 ›› Issue (3): 376-384. 上一篇    下一篇

研究论文

在线紫外-可见光谱研究ITO导电玻璃电极上苯胺与对苯二胺的电化学共聚及其产物的表征

张贵荣,徐承天,张爱健,陈丽,陆嘉星*   

  1. (华东师范大学化学系 上海市绿色化学与化工过程绿色化重点实验室 上海 200062)
  • 投稿日期:2007-05-22 修回日期:2007-09-25 发布日期:2008-02-14
  • 通讯作者: 陆嘉星

Study on Electrchemical copolymerization of aniline with p-phenylenediamine on ITO electrode by in situ UV-vis Spectroelectrochemistry and Characterization of the copolymer

ZHANG Gui-Rong; XU Cheng-Tian; ZHANG Ai-Jian; CHEN Li; LU Jia-Xing*   

  1. 华东师范大学化学系
  • Received:2007-05-22 Revised:2007-09-25 Published:2008-02-14
  • Contact: LU Jia-Xing

本文用在线紫外-可见光谱电化学的方法较详细地研究了在0.5M硫酸水溶液中苯胺、对苯二胺以及苯胺与对苯二胺混合体系在ITO导电玻璃电极上的电化学聚合和共聚合的过程。苯胺与对苯二胺在ITO导电玻璃上发生了电化学共聚合,在0.5M硫酸水溶液的纯苯胺和苯胺与对苯二胺共聚时的循环伏安曲线以及其对应的在线紫外-可见光谱表明对苯二胺的加入除了发生共聚外,也使聚合的速率明显加快;而且纯苯胺在循环伏安电化学聚合时在430nm处出现的吸收带因对苯二胺的加入而消失,说明对苯二胺的加入使聚合的机理与纯苯胺的聚合机理有明显不同,主要原因是苯胺产生的反应中间体可能很快与对苯二胺的阳离子自由基反应聚合。在导电玻璃ITO上的聚合物膜的反射傅立叶红外光谱表明,对苯二胺的加入可能产生了具有1,2取代模式结构,这说明了对苯二胺结合进入到聚合物中。这种共聚使得产物的表面形貌也发生了变化,聚合物扫描电镜图表明对笨二胺的加入有利于纤维状的表面形貌产生,纤维的直径可达到50nm粗细;同时用在线紫外-可见光谱研究了纯聚苯胺和共聚物随电位变化的电变色性质,结果表明在0v-0.6v之间共聚物与纯聚苯胺的在线紫外-可见光谱有明显的不同,且共聚物的电变色可逆性比纯聚苯胺好;同时SEM图也表明在0.8v电位下聚苯胺和共聚物表面形貌发生了团聚。

关键词: 苯胺, 对苯二胺, 电化学共聚,紫外-可见光谱, 傅立叶变换红外光谱

The electropolymerrization of p-phenylenediamine,and the electrocopolymerization between aniline and p-phenylenediamine in 0.5M H2SO4 on ITO electrode was studied was studied in detail by in situ UV-vis spectrometry. It was observed by in situ UV-vis spectrometry the polymerization of p-phenylenediamine and the electrocopolymerization between aniline and p-phenylenediamine happened by cycling potential scan electrolysis. Experimental results showed that the absorbance band at 430nm in in situ UV-Vis spectrum ,the characterization of intermediate during the electropolymerization of aniline, disappeared because of the presence of p-phenylenediamine. It was a direct evidence that indicated the addition of p-phenylenediamine changed the mechanism of the electro-polymerization of aniline on ITO electrode in 0.5M sulfuric acid solution. FTIR spectra of films deposited on ITO electrode was obtained and showed that 1,2 or 1,2,3 substituted modes could exist in the copolymer films. The SEM images of the films showed the additional p-phenylenediamine could changed markedly morphology of films and promoted the growth of fabric morphology with large area. For 20mM aniline+ 2mM PPDA in 0.5M sulfuric acid, the diameter of fiber in film grown on ITO electrode might reach 50nm.The electrochromic behaviors of polymer films were studied in detail. The in situ spectrum of copolymer film deposited on ITO electrode was evidently different from that of polyaniline film on ITO electrode at potential from 0.0v to 0.6v.The electrochromic reversibility of copolymer was better than that of polyaniline. Furthermore, SEM images of polyaniline and copolymer after electrolyzing them at 0.8v for 20 minutes showed aggregation happened on polyaniline granular film and copolymer fibrous film after electrolyzing them at higher potential.

Key words: Aniline, p-phenylenediamine, electrocopolymerization UV-vis spectrometry, FTIR