基于季铵化加成型聚降冰片烯及其纳米二氧化硅复合阴离子交换膜的制备与性能

发布时间：2018-04-20 11:04

本文选题：直接甲醇燃料电池 + 阴离子交换膜　；参考：《南昌大学》2015年硕士论文

【摘要】：燃料电池作为一种环境友好型的新型可持续动力能源技术,因其能量转换效率高、功率密度大以及较低的污染,已经受到广泛的关注和研究。而在其主要的燃料氢气和甲醇中,由于甲醇在储存和运输上的优势,因此直接甲醇燃料电池(DMFC)更具有发展的前景。目前,DMFC作为一种移动便携式的电源,已经可以应用于一些小型的手机电池和电动车电源中。但是,DMFC也存在两个主要的难题,一是目前研究较为成熟的质子交换膜直接甲醇燃料电池(PEMDMFC)必须使用如铂等贵金属材料,成本难以控制:二是甲醇在电池间的渗透率较高,质子交换膜的阻醇能力较差,易导致燃料损失从而影响电池性能。阴离子交换膜直接甲醇燃料电池(AEMDMFC)正可以有效地解决这一难题,在碱性条件下,电池阴极上O2动力学反应速度较高,因此可以使用非贵金属催化剂从而降低成本,另外,由于碱性燃料电池中OH-的传输方向与甲醇渗透方向相反,一定程度上可以抑制甲醇燃料的渗透,降低甲醇渗透率。因此,其关键部件阴离子交换膜(AEM)已经成为了国内外研究的热点之一。目前阴离子交换膜作为一种电解质膜,存在着电导率和稳定性偏低等问题,因此改善提高AEM的综合性能对促进AEMDMFC的发展具有十分重要的意义。本论文从聚合物结构设计及掺杂改性的角度出发,通过对加成型聚降冰片烯材料的功能化改性,借助其主链刚性双环结构的优点,期望制备得到具有高热稳定性、良好的机械性能及阻醇性能、优异的介电性和化学稳定性的阴离子交换膜材料。首先将侧链含有柔性基团的5-降冰片烯-2-亚甲基庚基醚(HN)和侧链带胺基的功能化降冰片烯单体3-(5-降冰片烯-2-亚甲氧基)-N,N-二甲基丙胺(NA)在以双(苯并环己酮苯亚胺)镍(Ⅱ)为主催化剂和以B(C6F5)3为助催化剂的二元催化体系下进行加成共聚合,通过调节单体加入的摩尔量合成出不同插入率的侧链具有后期可功能化改性的降冰片烯共聚物P(HN/NA)。该体系表现出较高的催化活性,且得到的共聚物分子量均较高。将得到的共聚物进行季铵化及碱性化处理并制备得到可传导OH-的阴离子交换膜材料。制备得到的QBnP(HN/NA)膜均具有高的热稳定性、优异的阻醇性能以及良好化学稳定性和机械性能,80 oC下测得其最大的离子传导率为3.58×10-3S/cm。再将直接带有季铵盐功能基团的三甲氧基硅基丙基氯化铵(TSPCA)通过溶胶凝胶的方式引入到聚降冰片烯中去,制备得到具有更高的热稳定性、化学稳定性、以及更好的离子传导能力的季铵化聚降冰片烯/纳米二氧化硅(QPDN/SiO2)杂化复合阴离子交换膜。其中,QPDN/SiO2-25(TSPCA相对于纯聚降冰片烯膜基质QPDN的质量分数为25%)表现出最好的性能,其最大离子传导率为9.33×10-3 S/cm,甲醇渗透率2.89×10-7 cm2/s也远低于商业化的Nafion膜(2.37×10-6cm2/s)。将QPDN/Si O2-25组装成膜电极,在甲醇/空气体系及80oC的条件下测得其开路电压为0.65 V,功率密度为32 mW/m2。实验表明,将无机纳米粒子均匀地引入到聚合物基质中对膜进行掺杂改性能有效提高膜的综合性能,通过对AEM的电导率和稳定性的进一步优化有望能应用于直接甲醇燃料电池中。
[Abstract]:As a new and environmentally friendly sustainable energy technology, fuel cell has been widely concerned and studied because of its high energy conversion efficiency, high power density and low pollution. In its main fuel hydrogen and methanol, the direct methanol fuel cell (DMFC) is the advantage of methanol in storage and transportation. At present, as a mobile portable power source, DMFC has been used in some small cell phone batteries and electric vehicle power sources. However, there are two major problems in DMFC. One is that the mature proton exchange membrane direct methol fuel cell (PEMDMFC) must be used as platinum and other precious metals. The cost is difficult to control: two is the high permeability between the methanol in the battery and the poor ability of the proton exchange membrane to resist alcohol, which is easy to cause the fuel loss and affect the battery performance. The anion exchange membrane direct methanol fuel cell (AEMDMFC) can effectively solve this problem. Under the alkaline condition, the O2 dynamic reaction speed on the battery cathode. Therefore, it is possible to use non precious metal catalysts to reduce the cost. In addition, because the transmission direction of OH- in basic fuel cells is contrary to the direction of methanol permeation, the permeability of methanol fuel can be suppressed to a certain extent and the permeability of methanol is reduced. Therefore, the key component of the anion exchange membrane (AEM) has become a hot research heat at home and abroad. At present, as a kind of electrolyte membrane, the anion exchange membrane has the problems of low conductivity and low stability. Therefore, it is of great significance to improve the comprehensive performance of AEM to promote the development of AEMDMFC. This paper is based on the design of polymer structure and doping modification, through the addition of polynorlene materials Functional modification, with the advantage of its main chain rigid double ring structure, is expected to prepare anionic exchange membrane materials with high thermal stability, good mechanical and alcohol resistance properties, excellent dielectric and chemical stability. First, the side chain containing the flexible group of 5-, -2- methylene heptane ether (HN) and the side chain aminopryl group The functionalized norbornene monomer 3- (5- norbornene -2- methoxy) -N, N- two methylanamine (NA) are copolymerized under the two element catalytic system with double (benzo cyclohexanone benzimide) nickel (II) catalyst and B (C6F5) 3 as the promoter, and the side chain with different insertion rates is synthesized by adjusting the molar content of the monomer. The functional modified norbornene copolymer P (HN/NA) has high catalytic activity, and the molecular weight of the copolymer is high. The obtained copolymers are prepared by quaternation and alkaline treatment and prepared to obtain the anion exchange membrane materials that can conduct the OH-. The prepared QBnP (HN/NA) films have high thermal stability. Excellent resistance to alcohol, good chemical stability and mechanical properties, the maximum ionic conductivity at 80 oC is 3.58 x 10-3S/cm., and then trimethoxy silicon propyl ammonium chloride (TSPCA) directly with quaternary ammonium salt functional groups is introduced into polynorlene through sol-gel, and a higher thermal stability is prepared. The quaternating polynorbornene / nano silica (QPDN/SiO2) hybrid anion exchange membrane has been shown to be the best performance of QPDN/SiO2-25 (TSPCA relative to the mass fraction of QPDN of the pure polycalenene membrane matrix 25%), and the maximum ionic conductivity is 9.33 x 10-3 S/cm. The alcohol permeability 2.89 x 10-7 cm2/s is also far lower than the commercialized Nafion film (2.37 x 10-6cm2/s). QPDN/Si O2-25 is assembled into a membrane electrode. The open circuit voltage is 0.65 V under the methanol / air system and 80oC, and the power density is 32 mW/m2.. The inorganic nanoparticles are evenly introduced into the polymer matrix for the film. Modification can effectively improve the comprehensive performance of the membrane. Further optimization of conductivity and stability of AEM is expected to be applied to direct methanol fuel cells.

【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ425.236;TM911.4

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