Engineering Atomically Precise Nanochannels Using Layered 2D Sheets to Enable Chemical Separation Membranes with Exceptional Permeance and Size-Selectivity

使用分层二维片设计原子级精确的纳米通道，使化学分离膜具有卓越的渗透性和尺寸选择性

• 批准号: 1705503
• 负责人: Michael Arnold
• 金额: $ 30万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1705503&HistoricalAwards=false
• 关键词: Engineering; Atomically; Precise; Nanochannels; Using

The separation of air into its components, oxygen, nitrogen, carbon dioxide, water vapor, and other trace gases such as helium, is a billion dollar industry. Examples include: use of purified nitrogen in high performance tires and infusion into specialty coffee; use of purified oxygen for healthcare and the launch space shuttles; use of helium for balloons. Separation of any mixture requires both energy and a strategy to isolate one component. Size selective membranes provide one such strategy, allowing molecules to permeate through internal channels at rates that are dictated by their ability to fit within a membrane channel, their diffusivity, and the strength by which they interact with the surface. Decreasing this surface interaction increases permeation, which translates to an increased production rate at lower energy consumption. One candidate for frictionless transport are membrane channels comprised of carbon atoms, such as cylindrical carbon nanotubes or stacked planar graphene sheets. As weak surface interactions provide little impediment to flow, the permeation of water through carbon nanotubes has been experimentally shown to be 1000 times greater than that predicted from classical models. Yet, homogenous channels of closely packed carbon nanotubes have been difficult to synthesize in large quantities. Propped graphene sheets show more promise for large scale synthesis, but are currently derived from graphite via a highly oxidative delamination process, which imparts significant residual oxygen atoms that invalidate frictionless transport. This project will utilize a bottoms-up nonoxidative approach to create propped graphene membranes with controlled channels optimized for size selective transport of small molecules, such as oxygen, nitrogen, hydrogen, helium, and water.This project will use molecular spacers as proppants to synthesize controlled nanochannels between pristine unoxidized parallel graphene sheets. Robust chemistries will be developed for precisely fabricating nanochannels with sub-nanometer gaps that range from 2-8 Angstroms to impart size selectivity. Candidate spacer molecules include para substituted benzene derivatives, functional groups grafted via [2+2] cycloaddition, and non-covalently adsorbed planar and non-planar aromatic hydrocarbons. Both isolated bilayer channels and multilayered laminate membranes will be fabricated. The isolated channels will afford fundamental surface science measurements of structure and properties whereas the multilayered membranes will enable macroscopic measurements of transport to validate the theoretical prediction of frictionless, ultrahigh permeance transport. Microstructural characterization data, in conjunction with transport measurements, will guide design of increasingly effective membrane materials. Both graduate and undergraduate students will perform laboratory research for this project, with an effort to target underrepresented groups. The research will inform interactive lessons targeted at high school level students, accompanied by dissemination of training videos to teachers.

空气将空气分离为其组件，氧，氮，二氧化碳，水蒸气和其他痕量气体（例如氦气）是一个十亿美元的行业。示例包括：在高性能轮胎中使用纯化的氮，并输注特种咖啡；将纯化的氧气用于医疗保健和发射空间班车；使用氦气作为气球。任何混合物的分离都需要能量和分离一个组件的策略。 尺寸选择性膜提供了一种这样的策略，使分子可以以内部通道的渗透，其速度取决于它们在膜通道内适应的能力，它们的扩散率以及它们与表面相互作用的强度。 减少这种表面相互作用会增加渗透率，这意味着在较低的能源消耗下的生产率提高。 无摩擦运输的一个候选者是由碳原子组成的膜通道，例如圆柱碳纳米管或堆叠的平面石墨烯。 由于弱的表面相互作用几乎没有流动的障碍，因此通过碳纳米管的水渗透到了实验中，比经典模型预测的水大1000倍。然而，紧密包装的碳纳米管的同质通道很难大量合成。 支撑石墨烯片对大规模合成表现出更多的希望，但目前是通过高度氧化分层过程从石墨中得出的，该过程赋予无效无摩擦转运的重要残留氧原子。该项目将利用一种自下而上的非氧化方法来创建具有控制型通道的支撑石墨烯膜，用于选择性的小分子的尺寸运输，例如氧，氮，氮，氢，氦气和水。该项目将使用分子间隔物作为proppant作为对受控的纳米芯氨基氨基氨酸固定型的proppant，以合成对受控的纳米氨基氨基氨酸脉络脉络脉络脉络脉络脉级。将开发出强大的化学成分，以精确制造具有亚纳米差距的纳米通道，范围从2-8埃词素到赋予尺寸的选择性。候选间隔分子包括para取代的苯衍生物，通过[2+2]环加成移植的官能团以及非可折叠吸附的平面和非平面芳族烃。将制造孤立的双层通道和多层层压板膜。孤立的通道将提供结构和特性的基本表面科学测量，而多层膜将实现宏观测量运输的测量，以验证无摩擦，超高渗透传输的理论预测。微结构表征数据与运输测量结果一起指导越来越有效的膜材料的设计。研究生和本科生都将为该项目进行实验室研究，并努力针对代表性不足的群体。这项研究将为针对高中学生的互动课程提供信息，并伴随着向老师传播培训视频。

项目成果

Invariance of Water Permeance through Size-Differentiated Graphene Oxide Laminates

• DOI: 10.1021/acsnano.8b02015
• 发表时间: 2018-08-01
• 期刊: ACS NANO
• 影响因子: 17.1
• 作者: Saraswat, Vivek;Jacobberger, Robert M.;Arnold, Michael S.
• 通讯作者: Arnold, Michael S.