Mesoscale modeling of self-assembly and transport in polymer electrolyte membranes

聚合物电解质膜自组装和传输的介观建模

• 批准号: 1207239
• 负责人: Alexander Neimark
• 金额: $ 38.38万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1207239&HistoricalAwards=false
• 关键词: Mesoscale; modeling; self; assembly; transport

TECHNICAL SUMMARYThis award supports theoretical and computational research and education to develop simulation methods to model structural and transport properties of polyelectrolyte membranes. Polyelectric membranes are one of the critical and most expensive components of the solid polymer electrolyte fuel cells, a promising technology for energy production from hydrogen and oxygen. A better understanding of the basic mechanisms of nanostructure formation and conductivity of polyelectrolyte membranes could lead to improvement of currently available solid polymer electrolyte fuel cells. Separation and transport properties of polyelectrolyte membranes are determined by their self-assembled nanostructure: upon hydration, the membrane segregates into hydrophilic and hydrophobic subphases on the mesoscopic scale. The PI aims to develop a mesoscale simulation method for studies of polyelectrolyte membranes self-assembly and proton conductivity based on the dissipative particle dynamics technique with coarse-grained interaction parameters determined from ab initio and atomistic molecular dynamics simulations. The new method includes the introduction of a mesoscopic model of proton transport along the hydrophilic subphase of the self-assembled polyelectrolyte membranes. The new method will be tested against available experimental data and earlier simulations of ionomer fragments and traditional Nafion membranes. The simulation method will enable direct computational investigation of segregated morphology and proton transport in coupled polyelectrolyte membranes. The PI aims to advance fundamental understanding of the physico-chemical mechanisms of self-assembly, water sorption and permeability, and proton conductivity. The simulation methods that will be developed and structure-property relationships that will be established have the potential to have significant impact and accelerate the search of new polyelectrolytes for permselective membranes for fuel cells, thus contributing to the effort to develop novel materials for sustainable hydrogen-based energy technologies. This award supports graduate, undergraduate, and postdoctoral training in theoretical and computational nanomaterials science and engineering. Minority undergraduate students will be recruited through the Rutgers special training programs. A dedicated webpage will be created for making project reports and presentations available for educational purposes. Computor codes together with instructive case study examples will be posted on this webpage for free distribution to the scientific community. Simulation methods developed and case-study systems will be included into a new graduate course on "Nanoscale Thermodynamics and Transport."NONTECHNICAL SUMMARY. This award supports theoretical research and education to develop computational methods for modeling structural and transport properties of polyelectrolyte membranes. Polyelectrolyte membranes are one of the critical and most expensive components of polymer exchange membrane fuel cells, a promising technology for the extraction of electric energy from hydrogen and oxygen. Polyelectrolyte membranes are made of complex chain molecules composed of hydrophobic and hydrophilic fragments. To function in a fuel cell, a polyelectrolyte membrane separates the two electrodes, the anode and the cathode, and allows only hydrogen ions or protons to pass through it leaving electrons behind. Hydrogen atoms, composed of a proton and an electron, are split at the anode liberating the electron that flows to the cathode through an electric circuit, for example the motor in an electric car. The proton flows through membrane to the cathode where it is reunited with the electron that has traveled trhough the circuit and oxygen atoms to form water which is expelled from the fuel cell. The ability of the polyelectrolyte membrane to conduct only protons is crucial for the operation of the fuel cell. Under working conditions, polyelectrolyte membranes exhibit a kind of self-assembly or restructuing of its molecules - the hydrophobic fragments form a three dimensional network of proton-conducting channels. The ability of the membrane to conduct protons depends of the specifics of the chemical composition and structure of the membrane that results from the self-assembly process. The PI will develop a novel computer simulation technique to determine the relationships among the chemical composition of the polyelectrolyte membrane, its structure under working conditions, and its ability to conduct protons, with the aim of determining optimal designs for novel fuel cell membranes. The results of this research could have impact across disciplines, since it addresses currently unresolved topical problems related to self-assembly and charge conduction in synthetic and biological polyelectrolyte materials. Computer modeling tools developed in the course of the research can be adapted and modified for simulation and optimization of other materials with potential to have application to biomedical systems and biomedical technologies involving DNA, proteins, and physiological membranes. This research contributes to the effort to develop sustainable energy sources.This award supports graduate, undergraduate, and postdoctoral training in theoretical and computational nanomaterials science and engineering. Minority undergraduate students will be recruited through the Rutgers special training programs. A dedicated webpage will be created for making project reports and presentations available for educational purposes. Computor codes together with instructive case study examples will be posted on this webpage for free distribution to the scientific community. Simulation methods developed and case-study systems will be included into a new graduate course on "Nanoscale Thermodynamics and Transport."

该奖项支持理论和计算研究和教育，以开发模拟方法来模拟生物膜的结构和传输特性。聚合物膜是固体聚合物电解质燃料电池的关键和最昂贵的组件之一，固体聚合物电解质燃料电池是从氢和氧产生能量的有前途的技术。更好地理解纳米结构形成的基本机制和导电性的质子交换膜可以导致目前可用的固体聚合物电解质燃料电池的改进。膜的分离和传输特性由其自组装的纳米结构决定：在水合作用下，膜在介观尺度上分离成亲水和疏水亚相。PI的目的是开发一种介观模拟方法，用于基于耗散粒子动力学技术的质子膜自组装和质子导电性的研究，粗粒度的相互作用参数从从头算和原子分子动力学模拟确定。新方法包括引入一个介观模型的质子传输沿着亲水亚相的自组装膜。新方法将测试对现有的实验数据和早期的模拟离聚物碎片和传统的Nafion膜。 模拟方法将使直接计算调查的隔离形态和质子传输耦合质子交换膜。PI旨在促进对自组装，吸水性和渗透性以及质子传导性的物理化学机制的基本理解。将开发的模拟方法和将建立的结构-性能关系有可能产生重大影响，并加速燃料电池选择性渗透膜的新型聚电解质的研究，从而有助于开发可持续氢基能源技术的新型材料。该奖项支持理论和计算纳米材料科学与工程的研究生，本科生和博士后培训。少数民族本科生将通过罗格斯大学的特殊培训计划招募。将建立一个专门的网页，以便为教育目的提供项目报告和演示文稿。电脑程式及具启发性的个案研究范例将上载于本网页，供科学界免费使用。模拟方法的开发和案例研究系统将被纳入一个新的研究生课程“纳米热力学和运输。“非技术性摘要。该奖项支持理论研究和教育，以开发用于模拟生物膜结构和传输特性的计算方法。 聚电解质膜是聚合物交换膜燃料电池的关键和最昂贵的组件之一，聚合物交换膜燃料电池是从氢和氧中提取电能的有前途的技术。聚电解质膜是由疏水性和亲水性片段组成的复杂链状分子构成的。为了在燃料电池中发挥作用，隔膜将两个电极（阳极和阴极）分开，并且只允许氢离子或质子通过，留下电子。氢原子由一个质子和一个电子组成，在阳极分裂，释放出的电子通过电路流到阴极，例如电动汽车的发动机。质子通过膜流到阴极，在那里它与穿过电路的电子和氧原子重新结合，形成水，从燃料电池中排出。质子交换膜只传导质子的能力对于燃料电池的运行至关重要。在工作条件下，质子交换膜表现出一种分子的自组装或重组-疏水片段形成质子传导通道的三维网络。膜传导质子的能力取决于由自组装过程产生的膜的化学组成和结构的细节。PI将开发一种新的计算机模拟技术，以确定燃料电池膜的化学成分、工作条件下的结构及其传导质子的能力之间的关系，目的是确定新型燃料电池膜的最佳设计。这项研究的结果可能会对跨学科产生影响，因为它解决了目前尚未解决的与合成和生物材料中的自组装和电荷传导相关的问题。在研究过程中开发的计算机建模工具可以进行调整和修改，用于模拟和优化其他材料，这些材料有可能应用于涉及DNA，蛋白质和生理膜的生物医学系统和生物医学技术。这项研究有助于开发可持续能源。该奖项支持理论和计算纳米材料科学与工程的研究生，本科生和博士后培训。少数民族本科生将通过罗格斯大学的特殊培训计划招募。将建立一个专门的网页，以便为教育目的提供项目报告和演示文稿。电脑程式及具启发性的个案研究范例将上载于本网页，供科学界免费使用。模拟方法的开发和案例研究系统将被纳入一个新的研究生课程“纳米热力学和运输。"