Engineering Selective Fuel Cell and Water Treatment Membranes

具有可控分离性能的膜在先进的能源和环境应用中发挥着重要作用。对于分离气体分子的聚合物膜，促进过选择性的潜在机制和结构-性质关系已经进行了非常详细的探索，但对于含有附着离子基团并吸收水的聚合物，如燃料电池膜，这些系统中为什么存在选择性以及如何通过合理的分子设计来增强选择性的潜在分子概念尚不清楚。气体分离膜和吸水膜的根本区别在于，气体分离膜中的输运过程主要受聚合物动力学控制，而吸水膜的输运性质主要受相对静止的聚合物基质中水的运动控制。因此，该项目将重点关注水-聚合物相互作用以及水在聚合物化学和物理框架内的结合和扩散的关键作用。智力优势：该研究的中心主题是研究含有磺酸基的末端连接聚合物系统，并确定设计燃料电池和纳滤膜的关键分子参数，这些膜对水、离子和小分子具有可调的选择性。具有良好控制结构变化的定制材料将推进我们对增加磺化聚合物选择性的不同途径的基本理解。表征任务将与合成工作密切结合，以探索膜的分子特性如何影响水的结合和扩散，以及反过来水的性质如何影响离子和小分子的运输。在分子、多纳米和膜长度尺度上对膜和传输特性进行深入研究，将使用光谱学、形态学分析和传输测量相结合的方法，特别关注化学和物理框架以及膜内的水结合。通过结合基本见解和性能特定的传输测量，可以形成这些重要材料的分子结构-传输特性的完整图像。更广泛的影响：该项目的成功将为含离子膜的发展开辟一个全新的方向，并对具有新结构和优越的选择性和传输性能的纳米结构膜的合理设计具有深远的意义。未来能够在聚合物膜和燃料电池跨学科领域工作的科学家将在该计划中接受培训和教育。本科生和少数民族将全面参与研究计划。“材料+创造力+社区=能量”模块包括讲座材料、讲义、幻灯片和动手实验演示，将在校园开放日、在校内外的学生团体活动（研讨会、学生俱乐部聚会、高中参观）以及两个新的暑期住宿营中创建和部署，包括宾夕法尼亚州立大学9-12年级教师的科学研讨会和ASM高中生材料营。

0932740WangProject SummaryMembranes with controllable separation properties play a vital role in advanced energy and environmental applications. Underlying mechanisms and structure-property relationships that promote permselectivity have been explored in great detail for polymer membranes that separate gas molecules, but for polymers that contain attached ionic groups and absorb water, such as fuel cell membranes, the underlying molecular concepts of why selectivity exists in these systems and how selectivity can be enhanced through rational molecular design are not clear. The fundamental difference between gas separation membranes and water-absorbing membranes is that the transport processes in gas separation membranes are dominated by the polymer dynamics where the water-absorbing membrane transport properties are dominated by the motion of water within the relatively stationary polymer matrix. Therefore, this project will focus on the critical role of water-polymer interactions and water binding and diffusion within the chemical and physical framework of the polymer. Intellectual Merit: The central theme of the proposed research is to study a system of end-linked polymers that contain sulfonate groups and to determine the critical molecular parameters for designing fuel cell and nanofiltration membranes with tunable selectivity for water, ions, and small molecules. The tailored materials with well-controlled structural variation will advance our fundamental understanding of the different routes to increasing selectivity in sulfonated polymers. The characterization tasks will be intimately integrated with the synthetic efforts to probe how the molecular characteristics of the membrane influence binding and diffusion of water, and in turn how the water properties influence the transport of ions and small molecules. An in-depth study of membrane and transport properties on the molecular, multi-nanometer, and membrane length scales will be performed using a combination of spectroscopy, morphological analysis, and transport measurements, with special attention paid to the chemical and physical framework and the water binding within the membrane. By combining both fundamental insights and performance-specific transport measurements, a complete picture of molecular structure-transport properties can be formed for these important materials.Broader Impacts: The success of this project will open a completely new direction in the development of ion-containing membranes and has profound implications for rational design of nanostructured membranes with new architectures and superior selectivity and transport properties. Future scientists capable of working in the interdisciplinary field of polymer membranes and fuel cells will be trained and educated within this program. Undergraduates and minorities will be integrally involved in the research program. The "Materials + Creativity + Community = Energy" modules including lecture materials, handouts, slides, and hand-on experimental demonstrations will be created and deployed in campus open houses, during student group activities on and off campus (seminars, student club gatherings, high school visits), and during two new summer residential camps including Penn State Science Workshop for grades 9-12 teachers and ASM Materials Camp for high school students.