电化学方法合成聚苯胺的研究
摘 要
膜科学技术自50年代以来发展迅速，现已在工业、农业、医学等领域获得广泛应用。就膜材料而言，有机膜发展最早，因其柔韧性好、成膜性能好、品种多等优点而获得大规模应用。聚苯胺电致变色膜作为一种导b电聚合物材料，具有易合成、均相、性质均一、能牢固附着在支持物上等优点具有广阔的市场应用前景。本文利用循环伏安法，采用三电极体系，研究在碳布电极表面合成聚苯胺膜。
本实验考查了苯胺单体浓度、溶液酸度、质子酸类型、线性扫描速率、扫描圈数等对合成聚苯胺膜的影响规律。实验发现聚苯胺的电化学氧化过程是一个自催化过程。镀液中苯胺单体浓度越大对成膜越有利，但是受苯胺的溶解度影响，镀液中的硫酸与苯胺的浓度比应大于1 : 1。另外降低扫描速率，适当增加扫描圈数有利于聚苯胺膜的形成，最佳扫描速率为25mv/s。聚苯胺的电化学活性明显依赖于质子化的程度，在苯胺与硫酸组成的镀液中，H2SO4浓度越大，膜的氧化还原可逆性越大，聚苯胺的自催化效应越强，质子酸中硫酸对聚苯胺的电化学生成的促进作用最大。
关键词： 聚苯胺，循环伏安，影响规律
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Abstract
The technology of film science has developed rapidly since the 1950s. It is widely used in industry, agriculture, medicine and other fields. The organic film was developed first. It is well applied in many filds because of its flexibility, film-forming properties, and has many kinds of product. The electrochromic display film of polyaniline is one of electronically conducting polymers, it has a broad market prospect because it is easily synthesized, character uniform and can be firmly attached to the substrates. The work studied synthesis of polyaniline film on carbon cloth with three elctrodes by means of cyclic voltammograms.
Synthesis of polyaniline films on carbon cloth are related to aniline concentration, solution acidity, bronsted acid type, linear scan rate and scanning numbers etc. It was found that the polyaniline electrochemical oxidation process is a self-catalytic process. It was found the higher the aniline concentration is, the esaier polyaniline synthesize is, because of the solubility of aniline in the water, sulfuric acid and aniline should be more than 1: 1 in concentration. Furthermore it was favorable to synthesize polyaniline films when reduce scan rate and increase the numbers of scanning appropriately, and the best scan rate is 25 mv/s. The activity of polyaniline films was significantly depended on the extent of the proton, in the solution of aniline and sulfuric acid bath, the greater the H2SO4 concentration is, the greater the film’s redox reversible is, the stronger the self-catalytic effect is ,and sulfuric acid can promote the speed of synthesis of
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polyaniline on the carbon cloth.
Key words: polyaniline，cyclic voltammograms，effect rules
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目 录
摘 要 ............................................................. 1 Abstract ........................................................... 2 第一章 绪 论 ....................................................... 6 1.1 引言 ........................................................... 6 1.2 聚苯胺的结构、颜色和导电性 ..................................... 7 1.3 聚苯胺的应用 ................................................... 8 1.3.1 在金属防腐上的应用 ........................................................................................................ 8 1.3.2 在电池方面的应用 ............................................................................................................ 9 1.3.3 在导电纤维上的应用 ........................................................................................................ 9 1.3.4 在电磁屏蔽材料方面的应用 ........................................................................................ 10 1.3.5 在抗静电方面的应用 ...................................................................................................... 10 1.3.6 在其它方面的应用 .......................................................................................................... 11 1.4 聚苯胺的合成方法 .............................................. 11 1.4.1 化学方法 ............................................................................................................................. 11 1.4.3 微乳液聚合 ........................................................................................................................ 12 1.4.4 电化学方法 ........................................................................................................................ 13 1.5 循环伏安法 .................................................... 16 1.6 本论文的工作 .................................................. 18 第二章 实验部分 ................................................... 18
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2.1 实验装置与仪器 ................................................ 18 2.2 化学试剂 ...................................................... 19 2.3 实验步骤 ...................................................... 19 2.3.1 碳纤维电极预处理 .......................................................................................................... 19 2.3.2 溶液配制 ............................................................................................................................. 20 2.3.3 聚苯胺膜的电化学制备 ................................................................................................. 20 第三章 结果与讨论 ................................................. 21 3.1 苯胺单体浓度对成膜的影响 ......................................................................................... 21 3.2 循环伏安扫描圈数对成膜的影响 ................................................................................ 23 3.3 循环伏安扫描速率对成膜的影响 ................................................................................ 25 3.4 酸度对聚苯胺在电极表面成膜的影响 ....................................................................... 26 3.5 质子酸类型对成膜的影响 .............................................................................................. 28 3.6 聚苯胺膜在碳布表面形貌观察 ..................................................................................... 29 第四章 结论 ....................................................... 31 参考文献 .......................................................... 32 致 谢 ............................................................ 35
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