Novel Nanostructured Membranes for Gas Separations

用于气体分离的新型纳米结构膜

• 批准号: 1403950
• 负责人: John Ferraris
• 金额: $ 39.85万
• 依托单位: University of Texas at Dallas
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1403950&HistoricalAwards=false
• 关键词: Novel; Nanostructured; Membranes; Gas; Separations

Ferraris, John 1403950 Novel Nanostructured Membranes for Gas Separations Polymer membranes for gas pair separations exhibit an inverse relationship between gas selectivity and gas flux. Maximizing both would be a significant advance. The idea of combining the selective separation properties of porous inorganic materials with the processability of polymers has resulted in several advances. Nevertheless, it appears that the performance of such membranes has reached a plateau, and a new approach will be needed to achieve a revolutionary breakthrough in membrane-based gas separations. The PIs have discovered that membranes constructed from otherwise immiscible polymers can be engineered at the nanoscale through the addition of small amounts of porous nanoparticles. The major limitation with current mixed matrix membranes (MMMs) for gas separations is their low gas flux, primarily due to the membrane thickness (several tens of micrometers) that is required to accommodate the porous additives. Colloidal ZIFs with particle diameters of 60 nm will enable the selective polymer layer to be submicrometer in thickness, and the matrix-droplet geometry will increase the interfacial surface area by 50 to 100X compared to a layer-by-layer morphology, greatly increasing flux while maintaining superior permselectivity. In order to fully utilize this novel membrane architecture, a thorough understanding of the thermodynamic and kinetic factors that control the structure will also be researched. Combining the selective separation properties of inorganic molecular sieves with the processability of polymers to form mixed-matrix membranes (MMMs) has resulted in several advances including the incorporation of porous additives such as metal organic frameworks (MOFs) and zeolitic imidazolate frameworks (ZIFs). The organic-inorganic hybrid nature of these additives has afforded improved interfacial contact with the polymer matrix, enabling very high loadings in the MMMs. The PIs propose a unique membrane architecture comprising blends of otherwise immiscible polymers that can be engineered at the nanoscale through the addition of small amounts of ZIFs. By choosing component materials with appropriate interfacial/surface tensions, the ZIF nanoparticles localize at the interface between the polymers. This has the advantage of compatibilizing high performance immiscible polymers thus greatly expanding the number of polymer combinations that can be utilized. The proposed research will develop membranes comprising thin, continuous ribbons of a highly selective polymer embedded in a discontinuous matrix of a second, highly permeable polymer, somewhat akin to the marbling in USDA Prime Beef. Such architectures will significantly improve the performance of membranes, especially by increasing flux and selectivity at lower additive loadings, thus reducing cost. This project on energy and the environment includes numerous tasks that will lead to the integration of research and multilevel education in the area of membrane science and novel nanomaterials. The replacement of energy intensive separations with membranes could result in economic savings. This level of structural control could also be potentially useful for fuel cell applications and other separations. Additionally, the strong educational component coinciding with the research activities will engage students at both the graduate and undergraduate levels, as well as students from underrepresented groups and women. The skills acquired by students during this project will enhance their preparation for careers in membrane engineering, nanotechnology, energy, and materials science. We are also committed to high school student research experiences and we anticipate that this project will also impact the community at large by educating our high school teachers and students.SIGNATURE Name: Rosemarie D. Wesson Title: Program Director Program: Chemical and Biological Separations DATE: April 2014

Ferraris, John 1403950 用于气体分离的新型纳米结构膜 用于气体对分离的聚合物膜表现出气体选择性和气体通量之间的反比关系。 最大化两者将是一个重大进步。 将多孔无机材料的选择性分离特性与聚合物的可加工性相结合的想法已经取得了一些进展。然而，此类膜的性能似乎已达到稳定水平，需要一种新方法来实现基于膜的气体分离的革命性突破。 PI 发现，通过添加少量的多孔纳米颗粒，可以在纳米级上对由不混溶的聚合物构建的膜进行改造。当前用于气体分离的混合基质膜（MMM）的主要限制是其气体通量低，这主要是由于容纳多孔添加剂所需的膜厚度（几十微米）。粒径为 60 nm 的胶体 ZIF 将使选择性聚合物层的厚度达到亚微米级，与逐层形态相比，基质-液滴几何形状将使界面表面积增加 50 至 100 倍，从而大大增加通量，同时保持优异的选择性渗透性。为了充分利用这种新颖的膜结构，还将研究控制结构的热力学和动力学因素的透彻理解。将无机分子筛的选择性分离特性与聚合物的可加工性相结合，形成混合基质膜 (MMM)，取得了多项进展，包括掺入金属有机骨架 (MOF) 和沸石咪唑酯骨架 (ZIF) 等多孔添加剂。这些添加剂的有机-无机杂化性质改善了与聚合物基质的界面接触，从而在 MMM 中实现非常高的负载量。 PI 提出了一种独特的膜结构，其中包含原本不混溶的聚合物的混合物，可以通过添加少量的 ZIF 在纳米级进行工程设计。通过选择具有适当界面/表面张力的组分材料，ZIF 纳米粒子定位在聚合物之间的界面处。其优点是使高性能不混溶聚合物相容，从而大大扩展了可利用的聚合物组合的数量。拟议的研究将开发一种膜，该膜包含一种高选择性聚合物的连续薄带，嵌入第二种高渗透性聚合物的不连续基质中，有点类似于美国农业部优质牛肉的大理石花纹。 这种结构将显着提高膜的性能，特别是通过在较低添加剂用量下提高通量和选择性，从而降低成本。这个关于能源和环境的项目包括许多任务，这些任务将导致膜科学和新型纳米材料领域的研究和多层次教育的整合。 用膜替代能源密集型分离可以节省经济。这种结构控制水平也可能对燃料电池应用和其他分离有用。此外，与研究活动相结合的强大教育内容将吸引研究生和本科生以及来自代表性不足群体和女性的学生。学生在该项目中获得的技能将增强他们在膜工程、纳米技术、能源和材料科学领域的职业准备。我们还致力于高中生的研究经验，我们预计该项目也将通过教育我们的高中教师和学生来影响整个社区。签名 姓名：Rosemarie D. Wesson 职位：项目总监 项目：化学和生物分离 日期：2014 年 4 月