童鞋论文网专业提供代写本科论文、代写硕士论文、代写职称论文、代写毕业论文、论文发表等服务,上万成功案例,欢迎咨询。 网站地图  |  加入收藏  |  设为首页
童鞋论文网
热门搜索
行政 教育 营销 法律 经济 护理 心理 会计 文学 工商 计算机 旅游
站内搜索:
童鞋论文网
 当前位置:童鞋论文网 > 专科论文 > 文章正文
 
基于乙烯基聚合物阴离子交换膜的制备与性能研究
论文作者:童鞋论文网  论文来源:www.txlunwenw.com  发布时间:2019/9/9 8:27:27  

摘要:燃料电池是一种高效、清洁的发电技术,它能够将燃料的化学能直接转换为可供电器使用的电能,它也被称之为新一代清洁能源。聚合物电解质膜燃料电池是品类众多的燃料电池当中被公认的最有发展潜质的燃料电池之一。将高分子聚合物材料作为电解质膜是这种电池最核心的技术,该类高分子膜在电池内部中既可以穿过离子,又可以隔离电池的阴阳两极防止内部短路。按照工作环境和输送离子的种类不一样能够将聚合物电解质膜划分成的只运送H+的质子交换膜(PEMs)和只运送OH-的碱性阴离子交换膜(AAEMs)。

与PEMFCs相比,AAEMFCs的电极两端的电化学反应活性更高,同时它的燃料渗透率也更低。更高的电极反应活性并且可以使用非Pt金属来替代Pt作氧化还原的催化剂,进而降低燃料电池的成本。AEMs电导率低和耐碱性差的缺陷仍然是AAEMFCs商业化进程中面临的巨大挑战。氢氧根离子体积较大,在介质中扩散速度和效果都要低于氢离子,导致其电导率与PEMs相比较低。且在高温高pH环境下阳离子基团和聚合物主链易受到氢氧根的亲核攻击,导致AEMs发生降解。

为了解决以上问题,本论文设计合成了耐碱性能优异的离子液体,并以乙烯基聚合物作为主链材料制备出一系列基于乙烯基聚合物的AEMs。通过乙烯基聚合物的引入为AEMs的材料提供了新的选择,也进一步改善AEMs的在高温强碱环境下的稳定性,本实验的研究内容如下:

(1) 合成了1-甲基-3-环氧丙基咪唑氯盐和1-甲基-1-环氧丙基哌啶氯盐两种离子液体,将其分别接枝到聚乙烯醇主链上,并通过戊二醛进行交联提高膜的机械性能和限制膜的溶胀度。经过溶液浇筑烘干得到两种不同阳离子的AEMs分别记为PVA-MIm、PVA-MPip。利用核磁共振氢谱(1H NMR)、红外光谱(FT-IR)等手段分别对小分子和聚合物膜官能团结构进行表征,详细研究了PVA-MIm和PVA-MPip的氢氧根传导率、力学性能、尺寸变化情况、热稳定性以及耐碱稳定性。该系列AEMs具有优异的机械性能和电导率,PVA-MIm和PVA-MPip膜在80oC下电导率分别可以达到19.8 mS cm-1和26 mS cm-1,且浸泡在1M的KOH溶液5天后电导率分别保留到原来的85%和88%,表明两种膜都具有较好的耐碱稳定性,但基于哌啶盐的PVA-MPip的耐碱稳定性稍好于咪唑盐的PVA-MIm膜。

(2) 采用两步法反应合成了带有双核结构的溴化1-乙烯基-3-(6-(1-丁基咪唑))己基咪唑盐[VBImHIm][Br]2,并通过1H NMR对[VBImHIm][Br]2的化学结构进行了表征;然后将[VBImHIm][Br]2与苯乙烯、丙烯腈混合均匀后,在紫外光照下聚合,制备得到碱性阴离子交换膜,使用红外吸收光谱(FT-IR)对AEMs的聚合物存在的官能团表征分析,并研究了该AEMs的各项性能。研究结果表明:该类AEMs形成了明显的亲-疏水相的微相分离结构,且拥有良好的尺寸稳定性、热化学稳定性、耐碱性以及较高的氢氧根传导率,其中在80oC下,[VBImHIm][Br]2含量为10%的阴离子交换膜电导率可达22 mS cm-1。

(3) 开发合成了一种耐碱性能优异的离子液体4-乙烯苄基-1-甲基-哌啶氯盐[MVBPip][Cl],通过光引发聚合和阴离子交换反应后,得到基于哌啶盐的AEMs。并系统地对膜的各项综合性能及其电化学性能等测试和研究。研究结果表明:随着离子液体[MVBPip][Cl]的含量增加,该系列AEMs的离子交换容量、泡水后的尺寸以及氢氧根电导率都增加。在原子力显微镜观察下,可以看到明显的亲-疏水相分离,为离子传输构建了连续的通道,其中AEMs离子液体含量为 30%的PSAN64-[MVBPip][OH]30在80oC下电导率能够达到57 mS cm-1。同时在2M KOH中浸泡480h依旧能保持不错的耐碱性,离子液体[MVBPip][Cl]的含量为25%的PSAN69-[MVBPip][OH]25组装单电池测试,最大功率密度可以达到66.5mW cm-2。

Fuel cell as a tool which could convertchemical energy into electrical energy and thermal energy. What has been recognizedas the next generation energy technology due to the higher efficiency andpollution-free advantages. There are many kinds of fuel cells, and polymerelectrolyte membrane fuel cell is one of the most promising one. Electrolytemembranes are the most important components of polymer electrolyte membranefuel cells, which play an important role in transporting ions and blockinganode and cathode. Based on the difference of the work environment andtransporting ions, the fuel cells could be classified as PEMFCs and AAEMFCs.

Compared with that of PEMFCs, AAEMFCs havelower fuel permeability, higher electrode kinetic and can use non-preciousmetals instead of Pt as catalysts, thereby reducing the cost of fuel cells.There is a huge challenge in the commercialization of AAEMFCs because of AEMs’low conductivity and poor alkaline stability. The diffusion coefficient ofhydroxide ion is lower than that of hydrogen ion, resulting in a lowerconductivity of AEMs than PEMs.

(1) Ionic liquids of 1-methyl-3-epoxypropylimidazoliumchloride and 1-methyl-1-epoxypropylpiperidine chloride were synthesized andgrafted to polyvinyl alcohol. In addition, glutaraldehyde is added forcrosslinking, which improves the mechanical properties of the membranes andlimits their degree of swelling. A series of crosslinked polyvinyl alcoholanion exchange membranes obtained by solution casting were recorded as PVA-MImand PVA-MPip, respectively. The structure was characterized by 1H NMR andFT-IR. The ion exchange capacity, mechanical properties, thermal stability,conductivity and alkaline stability of PVA-MIm and PVA-MPip were studied. TheAEMs showed excellent mechanical properties and high conductivity, and PVA-MImand PVA-MPip showed conductivities upto 19 mS cm-1 and 26 mS cm-1 at 80°C,respectively. The conductivity of PVA-MIm and PVA-MPip were retained to 85% and88% after 5 days in 1 M KOH solution at 65oC, which indicated the good alkalinestability of PVA-MIm and PVA-MPip.

(2) Binuclear bromide1-vinyl-3-(6-(1-butylimidazole) hexyl imidazole salt [VBImHIm][Br]2 wassynthesized by two-step reaction, and the chemical structure of [VBImHIm][Br]2was characterized by 1H NMR. Then, [VBImHIm][Br]2 was mixed with styrene andacrylonitrile uniformly, and the basic anion exchange membrane was prepared byultraviolet light-initiated polymerization. The structure and properties ofAEMs were systematically studied. The results show that the anion exchangemembranes have good dimensional stability, thermal stability and conductivity.The conductivity of AEMs with 10% content of [VBImHIm][Br]2 can reach 22 mScm-1 at 80°C.

(3) A facile strategy for the synthesis ofpiperidinium-based AEMs with excellent alkaline stability was developed by UVinitiated polymerization of 1-methyl-1-(4-vinylbenzyl) piperidinium chloride([MVBPip][Cl]). The chemical structure of [MVBPip][Cl] and piperidinium-basedAEMs were confirmed by 1H NMR and FT-IR spectroscopy, respectively. The wateruptake, swelling ratio, ion exchange capacity (IEC) and conductivity of piperidinium-basedAEMs increased with the increasement of [MVBPip][Cl] content in the membranes.Well-developed hydrophilic/hydrophobic phase separated morphology was observedfor piperidinium-based AEMs by AFM. And the transparent and mechanically robustpiperidinium-based membranes showed high conductivity up to 57 mS cm-1 at 80°Cand excellent alkaline stability in 2M KOH at 80°C. The single cell withpiperidinium-based membranes showed a maximum power density of 66.5 mW cm-2.

关键词:碱性阴离子交换膜;离子交换容量;氢氧根传导率;耐碱稳定

fuel cell; alkaline stability; ion exchangecapacity; conductivity;

上一篇:传统媒体地面频道创新发展研究     下一篇:多孔ETS-10沸石的合成、表征及其催化性能研究
 
论文客服 95702844
论文热线18796337551
本站网址 www.txlunwenw.com
郑重承诺 原创,包修改,包通过!
童鞋论文网真诚欢迎新老客户的光临与惠顾!
 
 热门文章
· 住宅建设用地使用权续期研究
· 用户锁定效应视角下的网易云音
· 众筹产品创新性对融资绩效的影
· 南京市城镇居民冷鲜肉认知度问
· 摩拜共享单车可持续盈利研究
· 催生地方政府隐性债务风险的原
· 社交媒体中不实信息转发主体心
· 基于网络平台的SPA模式研究——
· 基于游客感知的云台山景区微信
· 新媒体时代背景下乡村旅游企业
 
 推荐文章
· 论商业性小屏直播的主持互动策
· 新兴偶像经济发展现状及发展建
· 辅助线在小学生空间观念培育中
· 罗浮山国家级风景名胜区探险旅
· 基于《预算法》的地方政府债务
· 商品房买卖合同“霸王条款”存
· 中泰水果贸易竞争力比较分析
· 我国企业内部转移价格应用现状
· 虚拟现实技术下的创意短片《萌
· 核定征税与查账征税实施现状及
 
 相关文章
· 明末清初王学修正派社会政治思
· 《翰墨全书》利用的几个问题浅
· 东汉光武帝时期的将军号考略
· 明代莆田周氏家族作家群略考
· 美国文学这个野孩子——在德州
· 张载音乐思想初探
· 现代剧院的发展与变化探讨
· 清末民初的戏剧道具批评研究
· 多媒体技术在戏曲中的运用浅析
· 文化强省视角下的豫南民间艺术

论文原创,准时交稿,包修改,包通过,八年信誉,品质保证
童鞋论文网提供代写本科论文,代写专科论文,代写毕业论文,代写职称论文,代写硕士论文,论文发表及查重服务
备案号:苏ICP备11011187号-1 苏公网安备32030502000117号
版权归童鞋论文网所有 禁止一切商用盗用