【作者】 贾春悦；

【导师】 马利；

【作者基本信息】 重庆大学 ， 化学工程与技术， 2010， 硕士

【摘要】 聚苯胺(PANI)因其具有环境稳定性好、独特的掺杂机制、优异的电化学性能等优点,成为最重要的导电高分子材料之一。目前,PANI已广泛应用于实际生产应用中,如pH传感器、二次电池、膜材料以及防腐涂料等。磁场能影响含自由基(对)的化学反应,并诱导大多数有机聚合物分子和生物大分子的取向。由于PANI分子的抗磁性,其具有各向异性抗磁磁化率,将磁场引入聚苯胺的合成过程中,可使聚苯胺链更加规整、有序,有效提高聚苯胺的掺杂度、电导率、分子量和溶解性等。且两种或两种以上的表面活性剂复配,能起到增效、互相弥补各自性能缺陷的作用,即表面活性剂的协同效应。因此,本文利用利用表面活性剂的协同效应,制备十二烷基苯磺酸钠(SDBS)/聚乙二醇辛基苯基醚(TX-100)/正丁醇(nBA)/苯胺(An)/盐酸水溶液(HCl)微乳液聚合体系。并通过该微乳液聚合体系的拟三元相图,考察了恒定磁场(0.4T)、助表面活性剂(nBA)与复配乳化剂的质量比(Km=mnBA/mSDBS/TX-100)及SDBS与TX-100的质量比(Sm=mSDBS/mTX-100)对复合乳化剂/苯胺微乳液聚合体系的相行为和电导行为的影响。以碳纸负载PANI为工作电极,通过循环伏安和Tafel测试,探讨了磁场强度、复合乳化剂配比、乳化剂用量、氧化剂浓度和聚合时间对微乳液聚合法合成PANI电化学性能的影响;并通过对PANI的X射线衍射(XRD)、紫外光谱分析(UV)、电导率、产率以及特性粘度的表征分析,印证了其电化学性能分析结果的可靠性。研究结果表明,在复合乳化剂/苯胺/盐酸水溶液微乳液体系中,随着Km的增加,微乳区面积先增大后减小,当Km=1.0时,形成的微乳区面积最大;随着Sm的减少,微乳区面积逐渐增大;外加磁场可以增大微乳区面积,且随着Sm的减小,磁场对微乳液体系的作用逐渐减弱,通过对有、无外加磁场条件下溶液电导率随水含量变化规律分析,印证了拟三元相图的表征结果。循环伏安的测试结果表明,复合乳化剂微乳液法制备的聚苯胺,其循环伏安性能优于单组份乳化剂(SDBS或TX-100)微乳液法制备的聚苯胺。电导率和XRD分析结果表明,磁场条件下合成的PANI具有更高的导电性和规整度;紫外谱图分析表明,由于磁场的取向作用使分子间相互作用力降低,分子链离域程度增大,使磁场条件下合成PANI的主要特征吸收峰向低频方向移动。更多还原

【Abstract】 Polyaniline has been one of the most promising commercial conductive polymers, because of its advantages of unique doping-dedoping mechanism, excellent environmental stability and good electrochemical properties. Currently, it has been widely used in basic materials, such as pH-sensors, rechargeable batteries, membranes and corrosion-protecting coating.Magmetic field (MF) affect has a marked impact on free radical polymerization and induces the polumer orientation of most organic molecules and biological macromolecules. Because of the anti-magnetic of PANI, the molecules of PANI has anisotropic diamagnetic susceptibility, therefore, the introduction of MF into the synthesis process of PANI can obviously improve doping degree, conductivity, molecular weight and solubility of the PANI. Besides, two or more surface active agent mixture, can play a synergistic to each other to make up for the role of defects in their performance, and that is the synergistic effect of surfactants.Therefore, this paper prepared the microemulsion system of sodium dodecyl benzenesulfonate preparation (SDBS)/Triton X-100(TX-100)/n-butanol(nBA)/ aniline(An)/hydrochloric acid solution (HCl). The effects of the magnetic field(MF)(0.4T), the mass ratio of n-butanol(nBA) to composite emulsifier (Km=mnBA/mSDBS/TX-100) and sodium dodecylbenzenesulfonate(SDBS) to Triton X-100(TX-100)(Sm=mSDBS/mTX-100) on the phase behavior and conductivity of the microemulsion system during composite emulsifier/aniline polymerization were investigated by the pseudo-ternary phase diagram of SDBS/TX-100/nBA/An/HCl. The effects of preparation conditions such as the MF, the effects of the mass ratio of sodium dodecylbenzenesulfonate (SDBS) to Triton X-100(TX-100) and the amout of composite emulsifier(E) and oxidant(APS) and the polymerization time on the electrochemical properties of PANI were discussed by cyclic voltammogram and Tafel using the carbon paper loaded PANI as working electrode. The characterization results of the electrochemical properties of the products were proved by the analysis of the UV (UV), X-ray diffraction (XRD) and conductivity.The results showed that with the increase of Km, the area of microemulsion region increased initially and then decreased, the area reached the maximum on condition that Km is equal to 1.0; with the decrease of the Sm, the area increased gradually; the area was increased by the MF, and with the decrease of the Sm, the effect of MF on the microemulsion system was weakened. The characterization result of cyclic voltammogram(CV) showed that the CV property of the polyaniline prepared by microemulsion polymerization in the presence of composite emulsifier was better than that prepared in the presence of single emulsifier (SDBS or TX-100). Conductivityand XRD analysis result indicated that the PANI synthesized in the presence of MF there is significant on the crystalline degree and the conductivity properties. UV results indicated that the interaction force between molecules reduced, the delocalization of molecular chain increased, and the main characteristic absorption peaks of the PANI prepared in the presence of MF had the trend of moving to low-frequency due to the orientation of MF.更多还原