Modeling Solute Diffusion in Polymeric Membranes for Gas Separations

该奖项支持一种计算驱动的方法来开发聚合物膜的设计原则，为新兴技术提供有效的解决方案，如二氧化碳捕获和天然气净化。虽然在这一领域取得了许多进展，但其中大多数都是经经验性的-因此，可以合理地说，对控制这些膜材料分离能力的分子原理的定量理解很少。在这些事实的推动下，我们建议在各种模型上使用一套分子模拟方法来批判性地描述这些分离技术的基础，从那些与实验直接相关的模型到那些专注于提取普遍原理的模型。这项研究的成功完成可能会导致计算工具和基础知识的发展，从而促进针对当前和新兴清洁能源技术的聚合物膜的稳健设计方法。高渗透性，但选择性，聚合物材料将使高效，低成本，二氧化碳分离。这些研究工作将与一系列教育和外联活动相结合。受该组织最近成功招募高中生和大学生进行暑期研究的推动，该计划将继续招募来自历史上少数民族学校的学生，以及来自大纽约地区的本科生和高中生。PI的小组之前曾与几名后来决定在大学学习科学和工程的女性和少数民族高中生合作过。该建议是继续这种管道方法，以在科学和工程领域招募和留住代表性不足的少数民族。该奖项支持一种计算驱动的方法来开发用于膜应用的聚合物材料的设计原则-这种材料为新兴技术提供了有效的解决方案，例如二氧化碳捕获和天然气净化。这些聚合材料必须能够选择性和高效地输送气体。提出的研究的主要目的是通过使用一套分子模拟方法，从与实验直接相关的方法到专注于提取普遍原理的方法，批判性地描述控制聚合物膜分离过程的因素。PI的方法侧重于致密玻璃状聚合物的局部振动动力学，其特征是冻结矩阵的均方位移的长时间平台值。假设这是为了定义适当的动态“自由体积”度量。PI的小组将确定：这种动态的“自由体积”度量是否通用，是否有实验支持，以及它如何受到链刚度、链填料、溶质-溶剂相互作用、溶质尺寸和形状、基质的玻璃性以及诸如纳米颗粒等非均质性的影响。这将通过对这种关系的基本的、基于模拟的理解来实现。这项研究的成功完成可能会导致计算工具和基础知识的发展，这可能会促进当前和新兴清洁能源技术特定的聚合物和聚合物混合膜的设计方法。高渗透性，但选择性，聚合物材料将使高效，低成本，二氧化碳分离。这些研究工作将与一系列教育和外联活动相结合。在PI小组最近成功招募高中生和大学生进行暑期研究的推动下，该提案将继续招募来自历史上少数民族学校的学生，以及来自大纽约地区的本科生和高中生。PI的小组之前曾与几名后来决定在大学学习科学和工程的女性和少数民族高中生合作过。该建议是继续这种管道方法，以在科学和工程领域招募和留住代表性不足的少数民族。

Nontechnical SummaryThis award supports a computational driven approach to develop the design principles of polymeric membranes which present an efficient solution for emergent technologies, such as CO2 capture and natural gas purification. While there have been many advances made in this field, most of them have been performed empirically - consequently, it is reasonable to state that there is little quantitative understanding of the molecular principles that control the separation ability of these membrane materials. Driven by these facts, here we propose to critically delineate the underpinnings of these separation technologies using a suite of molecular simulation methods on a variety of models, going from those directly relevant to experiment to ones that focus in extracting universal principles. The successful completion of the proposed research could result in the development of computational tools and fundamental understanding that could facilitate robust design methodologies for polymeric membranes specific to current and emerging clean energy technologies. Highly permeable, but selective, polymeric materials will enable efficient, low-cost, CO2 separations. These research efforts will be coupled to a suite of education and outreach activities. Driven by the group's recent success in recruiting high school and undergraduate students for summer research, the proposal is to continue to recruit students from historically minority schools, as well as undergraduate and high school students from the greater New York City area. The PI's group has previously worked with several women and minority high school students who have subsequently decided to study science and engineering in college. The proposal is to continue this pipeline approach to recruit and retain underrepresented minorities in science and engineering fields.Technical SummaryThis award supports a computationally-driven approach to develop the design principles of polymeric materials for membrane applications - materials which present an efficient solution for emergent technologies, such as CO2 capture and natural gas purification. These polymeric materials have to be capable of selective and efficient transport of gases. The main objective of the proposed research is to critically delineate factors controlling separation processes in polymeric membranes by using a suite of molecular simulation methods, going from those directly relevant to experiment to ones that focus in extracting universal principles. The PI's approach is focused on the local, vibrational dynamics of a dense glassy polymer, as characterized by the long-time plateau value of the mean-squared displacement of the frozen matrix. This is postulated to define the appropriate dynamic "free-volume" metric. The PI's group will establish: if this dynamic "free-volume" metric is universal, if it has experimental backing, and how it is affected by chain stiffness, chain packing, solute-solvent interactions, the solute size and shape, the glassiness of the matrix, and the presence of heterogeneities such as nanoparticles. This will be achieved through a fundamental, simulation-based understanding of this relationship. The successful completion of the proposed research could result in the development of computational tools and fundamental understanding that could facilitate design methodologies for polymeric and polymer-hybrid membranes specific to current and emerging clean energy technologies. Highly permeable, but selective, polymeric materials will enable efficient, low-cost, CO2 separations. These research efforts will be coupled to a suite of education and outreach activities. Driven by the PI's group recent success in recruiting high school and undergraduate students for summer research, the proposal is to continue recruitment of students from historically minority schools, as well as undergraduate and high school students from the greater New York City area. The PI's group has previously worked with several women and minority high school students who have subsequently decided to study science and engineering in college. The proposal is to continue this pipeline approach to recruit and retain underrepresented minorities in science and engineering fields.