Collaborative Research: Reverse-Selective Membrane Materials for the Purification of Hydrogen and Other Light Gases

建议标题：用于氢和其他轻质气体净化的反向选择膜材料建议编号：CTS-0515425首席研究员：本尼·弗里曼研究所：得克萨斯大学奥斯汀分校这项合作提案的目标是制定和优化新一代气体分离膜材料，设计用于较大、极性或四极物种对较小、非极性物种的选择性渗透。这项工作中的膜材料是橡胶的、交联的共聚网络，专为实现较大的、极性或四极气体分子对较小的非极性分子的高溶解度选择性，同时最大限度地减少尺寸筛分而设计。该网络是由富含聚乙二醇酯的丙烯酸酯和双丙烯酸酯单体共聚而成的。在非优化膜上的初步渗透研究表明，基于聚乙二醇基的网络可以实现二氧化碳在氢气上的优先传输，迄今报道的非促进传输膜的二氧化碳渗透性和选择性的最高组合。这些先导研究还表明，气体分离性能对网络结构的细节很敏感，交联链密度和主干侧基的变化导致渗透性和总体选择性的显著变化。为了充分发挥这类新型膜的潜力，在制备和表征结构和交联密度可控变化的网络结构的基础上，提出了一项系统的实验研究。这些膜将经过战略性设计，以优化其分离特性和整体机械完整性方面的性能。了解网络结构和气体分离性能之间关系的关键是聚合物链动力学和局部自由体积，它们与膜的扩散系数和选择性有关。该项目将加强对橡胶网络的链动力学和形态与气体分离性能之间的关系的基本了解，并为这类工业相关的膜材料出现基于分子的设计范例。除了与该提案相关的基础材料和膜科学目标外，更广泛的影响还包括这些新膜作为基于吸收等繁琐、能源密集型方法的工业气体分离过程的替代品的潜在应用。这项工作将通过研究生培养产生重要的教育效益。此外，计划中的与液化空气公司的行业联系和与CSIRO(澳大利亚)的互动将提供关于气体分离膜的行业目标和优先事项的直接投入，并为这些材料的表征提供更多资源。这项工作可能导致一类新的膜用于工业上重要的气体分离。

AbstractProposal Title: Reverse-selective Membrane Materials for the Purification of Hydrogen and Other Light GasesProposal Number: CTS-0515425Principal Investigator: Benny FreemanInstitution: University of Texas at AustinThe objective of this collaborative proposal is the formulation and optimization of a new generation of gas separation membrane materials designed for the selective permeation of larger, polar or quadrupolar species over smaller, non-polar species. The membrane materials in this work are rubbery, crosslinked copolymer networks specifically formulated to achieve high solubility selectivity for larger, polar or quadrupolar gas molecules over smaller, non-polar molecules while simultaneously minimizing size sieving. The networks are prepared via copolymerization of polyethylene glycol (PEG)-rich acrylate and diacrylate monomers. Preliminary permeation studies on non-optimized membranes have demonstrated that preferential transport of carbon dioxide over hydrogen can be accomplished with PEG-based networks, with the highest combination of carbon dioxide permeability and selectivity yet reported for non-facilitated transport membranes. These pilot studies also indicate that the gas separation performance is sensitive to the details of the network structure, with variations in crosslink density and backbone pendant groups leading to significant changes in both permeability and overall selectivity. To fully realize the potential of this new class of membranes, a systematic experimental study is proposed based on the preparation and characterization of networks with controlled variations in structure and crosslink density. The membranes will be strategically designed to optimize their performance both in terms of separation properties and overall mechanical integrity. Keys to understanding the relationship between network structure and gas separation properties are the polymer chain dynamics and local free volume, as related to the diffusivity selectivity of the membranes. The project will lead to enhanced fundamental understanding as to the correlation of chain dynamics and morphology with gas separation performance for rubbery networks, and the emergence of molecular-based design paradigms for this industrially-relevant class of membrane materials. In addition to the fundamental materials and membrane science goals associated with the proposal, broader impacts include the potential application of these new membranes as replacements for industrial gas separation processes based on cumbersome, energy-intensive methods such as absorption. This work will lead to important educational benefits through graduate student training. Further, the planned industrial liaison with Air Liquide and interaction with CSIRO (Australia) will provide direct input regarding industrial goals and priorities for gas separation membranes, and expanded resources for the characterization of these materials. This work could lead to a new class of membranes for industrially important gas separations.