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1、华中科技大学博士学位论文 I摘 要 聚吡咯（PPy）属于典型的本征态导电高分子，具有容易制备、无毒害和良好的环境稳定性等优点。聚吡咯膜的电化学行为直接影响着其在很多领域的应用，因此对聚吡咯可逆的嵌入和脱出行为的基础研究意义重大。本文用循环伏安法（CV）和电化学交流阻抗方法（EIS）研究了电化学合成掺杂对甲苯磺酸根（pTS-）和十二烷基磺酸根（DS-）的聚吡咯膜（PPy/pTS 和 PPy/DS）在不同溶液中的离子交换行为，同时EIS还被用于研究过电位行为和嵌入聚吡咯膜的Na+和Cl-离子对聚吡咯膜特性的影响。结果表明 PPy/pTS 膜无法与溶液中较大尺寸（如 pTS-）或带有较高电荷（如 A
2、l3+）的离子进行电化学交换，其过电位现象只受阳离子的影响，且在 H+或只存在 Al3+情况下过电位现象进行不够完全。 在酸性溶液中 H+连同阴离子与聚吡咯的化学反应会取代电化学交换，其中较弱的对甲苯磺酸（HpTS）比较强的盐酸（HCl）与聚吡咯的化学作用更强更难脱附。另外，通过测试过电位前后和离子嵌入/脱出行为对聚吡咯膜的电化学交流阻抗的影响表明过电位过程能提高聚吡咯膜的离子电导率和膜电容， Cl-离子的嵌入对 PPy/pTS 膜的电导率有很大的提高而 Na+离子嵌入对聚吡咯膜的影响不大。 聚吡咯膜可逆的离子嵌入和脱出行为可以很好的用作电控制离子交换树脂材料，目前一般用循环伏安法来评价它的离
3、子交换性能。但循环伏安测试过程中会存在如双电层充放电和电解水等电化学反应，因此无法准确的评价聚吡咯的离子交换性能。本文通过模拟电控离子交换过程利用循环伏安电量差值消去其它电化学过程从而得到离子释放过程的电量（即离子交换电量） ，在此基础上提出离子交换率和全交换容量的计算方法，并借助电感耦合等离子质谱法（ICPMS）和离子色谱法（IC）验证了方法的正确性。然后利用该方法研究了聚合电流、掺杂阴离子（氯离子（Cl-） 、硝酸根（NO3-） 、对甲苯磺酸根（pTS-）和十二烷基磺酸根（DS-） ）和膜厚对聚吡咯的离子交换性能的影响，结果表明掺杂中等尺寸阴离子的 PPy/pTS 膜具有最好的阴离子交换行
4、为，而掺杂较大尺寸阴离子的 PPy/DS 膜具有最好的阳离子交换行为。另外聚合电流密度和膜厚对聚吡咯膜的离子交换性能也有一定的影响。 华中科技大学博士学位论文 II金属改性可以很好的提高聚吡咯的多种性能和扩展聚吡咯的应用，其中铜由于价格低廉且能与聚吡咯环上的 N 原子形成较强的化学键并能提高聚吡咯的环境稳定性和电导率而得到广泛的研究。目前聚吡咯与铜的复合材料（PPy- Cu）主要通过两步直流法（TDC）得到，该法在第二步改性时生成的 Cu 单质会堵塞聚吡咯膜的孔隙结构而使得膜的深层无法得到充分改性。本文针对该问题采用一步电位脉冲法（Pulse）将聚吡咯的合成和铜的改性在合成过程中同时进行以得到
5、更为均匀的 PPy- Cu 膜。本文分别用 Pulse 和 TDC 法制备了 Polypyrrole/Sulfate- Copper（PPy/SO4- Cu）复合膜，并通过环境扫描电子显微镜（SEM） 、X 射线能谱仪（EDS）、X 射线衍射仪（XRD）和 X 射线光电子能谱仪（XPS）研究了膜的表面形貌、物相成分和元素价态。并通过热重分析仪（TGA）、CV 和 EIS 研究了不同聚吡咯膜的热稳定性和碱性稳定性。结果表明不同方法合成的聚吡咯均具有相同的无定形结构， PPy/SO4- Cu膜中的铜主要以Cu+形式与吡咯环上的 N 原子结合形成化学键，其中 Pulse 法比 TDC 法制备的聚吡咯
6、具有更高的 Cu 含量、更小的颗粒和更多的孔隙结构。另外，Pulse 法较 TDC 法制备的聚吡咯具有较高的 N+含量和更少的氧化态碳比例， 表明脉冲方法还能更好的保护聚吡咯的主链结构使得聚吡咯膜具有更高的掺杂度和较少的碳链损伤。Cu 的修饰改性并不能提高聚吡咯膜的热稳定性，特别是脉冲合成的 PPy/SO4- Cu 的热稳定性明显较差。但 Pulse 方法合成的 PPy/SO4- Cu膜具有更好的碱性稳定性，其原因可能是脉冲合成的聚吡咯膜具有更致密的结构和对膜更充分和更均匀的铜修饰改性。最后由于具有更多的孔隙结构，脉冲合成的 PPy/SO4- Cu膜的比电容量明显较高。 关键词： 聚吡咯；电化
7、学聚合；循环伏安；交流阻抗；离子交换； 碱性稳定性；超电容； 华中科技大学博士学位论文 IIIAbstract Polypyrrole (PPy) is a typical conducting polymer with many advantages such as ease of preparation, special electronic and electrochemical properties, harmlessness and good environmental stability. The electrochemical property of PPy is very im
8、portant because a lot of applications are based on the reversible ions insertion and ejection processes, so it is necessary to study the influence of synthesis and measurement conditions on its ions exchange behaviors. The ions exchange behaviors of PPy films doped with p- toluenesulfonate anion (pT
9、S-) and dodecyl sulfonate anion (DS-) (PPy/pTS and PPy/DS) films in different solutions were investigated by means of cyclic voltammetry (CV) and electrochemical impedance (EIS), and the influence of overpotential during first reduction and Na+ or Cl- insertion on the PPy films was also studied by E
10、IS. The results showed that the PPy/pTS film can not exchange with large size ions (pTS-) and high valence ions (Al3+), and its overpotential behavior was mainly due to cation insertion and can not be performed completely in solutions including only H+ or Al3+ cations. In an acidic solution, some of
11、 the electrochemical exchange especially the cation exchange process will be instead by chemical doping, and the absorption of weak acid (p- toluenesulfonate acid, HpTS) in PPy film was stronger than strong acid (hydrochloric acid, HCl). In addition, the EIS of PPy/pTS films in different condition s
12、howed that the overpotential process would improve the ionic conductivity and film capacitance and insertion with Cl-will improve the films electronic conductivity, however, insertion with or without Na+ showed little difference in EIS. The reversible ion exchange behavior of PPy can be employed for
13、 electrically switched ion exchange resin. At present, the ion exchange ability was evaluated by CV method, which can not describe the exact amount of exchanged ions because that part of the CV charge was arises from other process such as the charge and discharge of electrochemical double layer. In
14、this case, the simulation experiments of removal of ions from solution were designed, and after subtracting the same electrochemical processes, the ion exchange charge coming from ejection of the inserted ions can be obtained, which were 华中科技大学博士学位论文 IVproved by inductively coupled plasma mass spect
15、rometry (ICPMS) and ion chromatography (IC). Based on this charge, the ion exchange ratio and the operating exchange capability of PPy films also can be counted, all of which can be used for evaluating the ion exchange ability of PPy films. And then, the ion exchange behavior of PPy doped with a var
16、iety of dopants, namely chloride, nitrate, pTS- and DS-, was investigated by means of CV in NaCl, NapTS and AlCl3 aqueous solutions. Among these films, PPy/pTS (doped with the medium sized counterion pTS-) showed the best anion exchange ability, while PPy/DS (doped with the large counterion DS-) exhibits the best cation exchange ability. In addition, the synthesis current density and thickness of PPy films also affected its ion exchange ability. Many metals can be combined with PPy matrices to
