【作者】 葛东涛；

【导师】 王世昌；

【作者基本信息】 天津大学 ， 化学工程， 2003， 博士

【摘要】 聚吡咯具有稳定性好、掺杂后导电性高等优点。但由于其在通常情况下不易溶解和熔化，加工性能差，限制了它的应用。目前用于改善导电聚合物加工性的方法主要有取代法和掺杂法两种，但这两种方法均以牺牲导电聚合物的导电性为代价。理想的方法是使导电聚合物在制备过程中直接形成某种特定形状，而不是在制备之后再改善其加工性能。聚吡咯纳米线正是在这一思想指导下直接形成的一种一维纳米材料，它兼具导电聚吡咯和一维纳米材料的共同优点，是当前纳米材料领域备受瞩目的研究课题之一。但是，现有的制备聚吡咯纳米线的方法通常具有成本高、产率低、操作复杂、所需制备时间长等缺点。在这样的背景下，本研究对聚吡咯纳米线的制备方法进行了新的探索。论文工作主要包括以下内容：从高分子诱导物与吡咯单体之间的化学作用出发，提出可溶性高分子诱导制备聚吡咯纳米线的新概念，并在这一概念的指导下，采用电化学聚合法分别在乙烯基吡咯烷酮-顺丁烯二酸酐交替共聚物（PVP-MA）、聚丙烯酸（PAA）、乙烯基吡咯烷酮-苯乙烯交替共聚物（PVP-PS）和肝素钠（Heparin sodium salt）等四种可溶性高分子的诱导下成功制备出直径范围为70~110 nm的聚吡咯纳米线。这是本论文首创的制备聚吡咯纳米线的新方法。与其它制备聚吡咯纳米线的方法相比，该法具有制备时间短（30~300 s）、操作简便、成本低、所得聚吡咯纳米线直径和长度可控等优点；同时，采用该法制备的聚吡咯纳米线经高氯酸处理后具有优良的导电性，其电导率可达65~100 S/cm。采用电化学法和扫描电镜法研究了可溶性高分子存在时聚吡咯纳米线的成核与生长过程，结果表明当PVP-MA，PAA和肝素钠存在时，聚吡咯的成核属三维瞬时成核机理；当PVP-PS存在时，聚吡咯的成核属三维逐步成核机理。而其生长机理则与高分子种类无关，随聚合电位的不同分别遵循二维生长机理和三维生长机理。分析了聚吡咯纳米线取向性与可溶性高分子之间的关系，提出了聚吡咯纳米线线型形貌形成的控制机理，并用不同直径纳米线之间导电性的差异证明了这一机理的正确性。系统考察了影响聚吡咯纳米线形貌的各种因素，发现其形貌与聚合电位、吡咯单体浓度、可溶性高分子浓度、高氯酸锂浓度以及聚合时间等有关，而与电化学制备方法和电极材料（石墨、导电玻璃和不锈钢）无关。更多还原

【Abstract】 Polypyrrole (PPy) is one of the excellent conducting polymers with good stability and high conductivity. The low solubility and infusibility restrict its processing and applications in some fields. The main methods to improve the processibility are adding substitution groups onto polypyrrole and doping with large dopants. PPy synthesized by the two methods will lose its conductivity to certain extent. To circumvent this problem, the best strategy is to prepare polypyrrole directly in the procedure of processing, rather than after it. PPy nanowires, in this thesis, are just the one-dimensional materials prepared under the instruction of such strategy. It has advantages of both conducting polymers and one-dimensional materials. Therefore, studies on the PPy nanowire have become one of the most attractive fields about nanomaterials. However, high cost, low productivity and difficult operation are the common disadvantages of the reported methods used for preparing PPy nanowires. Many efforts have been made in our laboratory to develop a new method for preparing PPy nanowires and explore the mechanism for the formation of PPy nanowires. The research results are mainly included as following:To control the growth of pyrrole by chemical interaction, a new strategy is proposed in this thesis to synthesize PPy nanowiews in the presence of soluble macromolecules that have functional groups to form hydrogen bond with pyrrole monomer. PPy nanowires with diameters of 70~110 nm are successfully prepared electrochemically in the presence of poly(maleic acid-co-vinyl pyrrolidone) (PVP-MA)、polyacrylic acid(PAA)、poly(maleic acid-co-styrene)、and heparin sodium salt. Compared to other methods used for preparing PPy nanowires, the method we used has many advantages for its very short preparation time (30~300 s), facile operation, low cost, and controllable length and diameters. Doping with perchlorate ion, the PPy nanowires prepared in this way will exhibit excellent conductivity (65~100 S/cm).The nucleation and growth mechanism of PPy nanowires was studied by electrochemical method and scanning electron microscopy. It was found that the nucleation of PPy is a three-dimensional instantaneous process in the presence of PVP-MA, PAA and heparin sodium salt; while the nucleation is a three-dimensional progress process in the presence of PVP-PS. The growth of PPy nanowires is a two- or three-dimensional process with the difference of applied potential and has no relationship with the soluble macromolecule. The relationship between the orientation of PPy and the soluble macromolecule was <WP=4>explored. The controlling mechanism for the formation of PPy nanowires was presented and the reliability of the mechanism was proved by the different conductivity among the nanowires with different diameters.The influences of related parameters on PPy morphology were systemically investigated. The experimental results indicate that PPy morphology could be influenced by applied potential, pyrrole concentration, lithium perchlorate concentration, soluble macromolecule concentration, and polymerization time. However, the electrochemical preparation methods and the electrodes (graphite electrode, ITO electrode and stainless steel electrode) have no effects on PPy morphology.更多还原