Systematic Control of the Crystalline Morphology in Perfluorosulfonate Ionomer Membranes

CBET-0756439 Moore这个基础项目旨在填补我们对现代燃料电池膜中主链有序堆积所产生的聚合物晶体的形式和功能的理解中的关键空白。 虽然我们已经了解了很多关于质子传导离子域的功能聚合物，如全氟磺酸盐离聚物（PFSI）Nafion的组织，值得注意的是，我们知道很少的详细结构和形成的微晶在这些材料或这些有序功能的空间排列相对于离子域的接近。 与这些技术上重要的聚合物的形态学研究的绝大多数，这个项目将集中在？其他人呢？这些膜中的重要形态特征，即结晶组分的关键意义。 本项目的实验方法将涉及（1）系统控制PFSI结晶度和组织的方法的开发和改进，（2）结晶组分的结构表征，以及（3）受结晶顺序影响的燃料电池相关性能的分析。 通过定制的膜加工和目前可用的具有较短功能侧链结构的新的高度结晶的PFSI提供的可控范围的堆叠，我们将能够最终分离该属性在膜性能/耐久性中的具体贡献，并允许全面了解导致质子交换膜燃料电池（PEMFC）应用中的有效能量转换的形态因素。 这项研究将影响基本修改用于PFSI膜，专注于更有序的结晶域的发展，传统的工艺参数，并刺激膜设计和制造的多学科方法。 从社会影响的角度来看，预计这一特定领域的基础研究将实现更高效，更强大和可持续的能源转换，同时对环境的影响较小。 参与该项目的学生将接触到最先进的形态表征方法，膜制造的工程方面，以及燃料电池科学的现代技术。 在这项工作的过程中开发的教育模块将被纳入在弗吉尼亚理工大学的科学和工程项目的扩大能源课程。

CBET-0756439MooreThis fundamental project is aimed at filling a critical void in our understanding of the form and function of polymeric crystals produced by the ordered packing of backbone chains in modern fuel cell membranes. While we have learned a great deal about the organization of the proton-conducting ionic domains in functional polymers such as the perfluorosulfonate ionomer (PFSI) Nafion, it is remarkable that we know very little about the detailed structure and formation of the crystallites in these materials or the spatial arrangement of these ordered features with respect to the proximity of the ionic domains. In contrast to the vast majority of morphological studies of these technologically important polymers, this project will be focused on the ?other? important morphological feature in these membranes, namely the critical significance of the crystalline component. The experimental approach in this project will involve (1) development and refinement of methods to systematically control the degree and organization of crystallinity in PFSIs, (2) structural characterization of the crystalline component, and (3) analysis of the fuel cell relevant properties impacted by the crystalline order. With a controlled range of crystallinities provided by tailored membrane processing and new, highly crystalline PFSIs currently available with shorter functional sidechain structures, we will be able to finally isolate the specific contributions of this attribute in membrane performance/durability and allow a comprehensive understanding of the morphological factors that lead to efficient energy conversion in proton exchange membrane fuel cell (PEMFC) applications. This research will impact fundamental modifications to the conventional processing parameters used for PFSI membranes that focus on the development of more ordered crystalline domains, and stimulate a multi-disciplinary approach to membrane design and fabrication. From a societal impact perspective, it is anticipated that fundamental research in this specific area will enable a more efficient, robust, and sustainable energy conversion with low environmental impact. Students involved in this project will be exposed to state-of-the-art methods of morphological characterization, engineering aspects of membrane fabrication, and the modern technology of fuel cell science. Educational modules developed in the course of this work will be incorporated in the expanding energy curriculum of the Science and Engineering programs at Virginia Tech.