质子交换膜传递通道理性构筑及其微环境调控研究

发布时间：2018-03-25 02:40

  本文选题：质子交换膜　切入点：通道　出处：《天津大学》2016年博士论文

【摘要】：质子交换膜燃料电池(PEMFC)作为一种新型发电装置,具有高效率、零污染等特点,在能源领域发挥着重要作用。质子交换膜(PEM)是其“心脏”,决定电池功率。开发高传递性能PEM是实现PEMFC大规模应用的关键挑战。为此,必须从分子尺度到微纳米尺度揭示膜通道与传递特性之间的关联,为膜结构设计奠定基础。本研究以PEM的传递性能优化为主要目标,围绕膜材料定向设计-膜通道理性构筑-膜微环境协同调控-膜传递特性优化这一链条,融合仿生和杂化思想,揭示了微环境与传递特性之间关联,实现了传递特性的显著优化,以期为高性能PEM的规模化制备提供理论指导和技术支持。主要研究成果如下:膜化学微环境调控与质子传递过程强化。受植物保水机理启发,制备了亲疏水性可调变的羧酸微囊(PMCs),将其与磺化聚醚醚酮共混制备杂化膜。研究发现:PMCs在膜中发挥着“蓄水池”的作用,优化了传递通道的水环境(化学微环境),从而使膜在低湿度下的传导率增加13倍。制备了两性离子微囊(ZMCs),将其与Nafion共混制备杂化膜。研究发现:ZMCs能同时优化膜通道水环境和质子载体(化学微环境),强化了杂化膜在低湿度下的质子传导(提升21倍)。膜物理、化学微环境协同调控与质子传递过程强化。制备高分子功能化碳纳米管(FCNTs),将其与Nafion共混制备杂化膜。研究发现:FCNTs协同优化了膜通道物理、化学微环境,实现了质子传导的高效强化(提升5倍);在物理微环境方面,FCNTs在膜内构筑了高度连续的质子传递通道;在化学微环境方面,FCNTs含有高密度的离子基团。通过直接组装膦酸化氧化石墨烯纳米片(PGO),在PGO膜中构筑了贯穿型通道,克服了两亲性高分子膜在构筑通道方面的局限。在物理微环境方面,规则排列的GO纳米构筑了贯通于膜的超级连续通道;在化学微环境方面,膦酸基团能够独立形成动态氢键网络。膜物理、化学微环境协同调控与质子/甲醇传递特性优化。通过在Nafion膜表面组装超薄的氧化石墨烯(GO)膜,制备了复合膜。研究发现:由于对膜表层GO膜中传递通道的物理、化学微环境的协同优化,实现了质子传导率与阻醇性能同步提升。膜物理、化学微环境协同调控与质子传递和机械性能同步优化。通过组装二维无机材料与高分子SPVA,首次制备了仿珍珠层结构的PEM。研究发现:由于二维材料与高分子之间的协同作用,膜表现出超强的机械性能。同时,协同优化膜通道的物理、化学微环境,强化了质子传导率,膜在80 oC传导率达到364 mS cm-1,为目前报道的最优值之一。
[Abstract]:Proton exchange membrane fuel cell (PEMFC), as a new type of power generation device, has the characteristics of high efficiency, zero pollution and so on. PEM plays an important role in the field of energy. PEM is its "heart", which determines the battery power. The development of PEM with high transfer performance is a key challenge to realize the large-scale application of PEMFC. In order to lay a foundation for membrane structure design, the relationship between membrane channel and transport characteristics must be revealed from molecular scale to micro-nanometer scale. The main objective of this study is to optimize the transport performance of PEM. Around the chain of oriented design of membrane material, rational construction of membrane channel, cooperative regulation of membrane microenvironment and optimization of membrane transfer characteristics, the bionic and hybrid ideas are combined, and the relationship between microenvironment and transfer characteristics is revealed. In order to provide theoretical guidance and technical support for the large-scale preparation of high performance PEM, the main research results are as follows: membrane chemical microenvironment regulation and proton transport process are strengthened, inspired by the mechanism of plant water retention. The hydrophobic and adjustable carboxylic acid microcapsules (PMCs) were prepared and blended with sulfonated polyether ether ketones to prepare hybrid membranes. The water environment (chemical microenvironment) of the transfer channel was optimized to increase the conductivity of the membrane at low humidity by 13 times. The amphoteric ion microcapsule ZMCs was prepared and mixed with Nafion to prepare hybrid membrane. The channel water environment and the proton carrier (chemical microenvironment) enhance the proton conduction of the hybrid membrane at low humidity (increase by 21 times. Chemical microenvironment coordinated regulation and proton transfer process strengthening. FCNTs were prepared and blended with Nafion to prepare hybrid membranes. It was found that: FCNTs co-optimized the physical and chemical microenvironment of membrane channels. The proton conduction was enhanced by 5 times, and the FCNTs constructed a highly continuous proton transfer channel in the physical microenvironment. In the chemical microenvironment, FCNTs contain high density ionic groups. Through the direct assembly of phosphonated graphene oxide nanocrystals, a penetrating channel was constructed in the PGO film. It overcomes the limitation of amphiphilic polymer membrane in constructing channel. In physical microenvironment, the regular arrangement of go nanometre builds the super continuous channel through the membrane, and in the chemical microenvironment, The phosphonic acid group can form a dynamic hydrogen bond network independently. The membrane physical and chemical microenvironment coordinated regulation and the proton / methanol transport characteristics are optimized. The ultrathin graphene oxide (GluO) film is assembled on the surface of the Nafion film. The composite membrane was prepared. It was found that the proton conductivity and alcohol resistance were improved simultaneously because of the synergistic optimization of the transfer channels in the surface go membrane. By assembling two-dimensional inorganic materials and polymer SPVA, PEMs imitating the structure of pearl layer were prepared for the first time. It was found that due to the synergistic effect between two-dimensional materials and polymers, PEMs were prepared by chemical microenvironment coordination control and proton transfer and mechanical properties optimization. At the same time, the membrane exhibits excellent mechanical properties and enhances the proton conductivity by optimizing the physical and chemical microenvironment of the membrane channel. The conductivity of the membrane reaches 364mScm-1 at 80oC, which is one of the best reported values at present.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TB383.2;TM911.4
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本文编号：1661202