Understanding Gas Transport through Nanopores in Graphene Membranes

了解石墨烯膜中纳米孔的气体传输

• 批准号: 1907716
• 负责人: Michael Strano
• 金额: $ 30万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-15 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1907716&HistoricalAwards=false
• 关键词: Understanding; Gas; Transport; through; Nanopores

Industrial processes that separate chemical mixtures are essential for civilization, including, for example, the production of energy, materials, and commodity chemicals. The development of more selective and energy efficient separation processes is therefore an important technological challenge, promising the potential for substantial cost savings as well as reductions in energy consumption and harmful emissions. Most industrial separations are energy-intensive thermal processes, which account for 10-15% of the world's overall energy consumption. Membrane-based separation processes offer attractive alternatives to thermal separation techniques due to their reduced energy consumption and excellent reliability. However, the trade-off between gas flux and selectivity of conventional gas separation membranes has historically limited the overall performance of a membrane separation unit, as well as the motivation for replacing energy-intensive processes with these more efficient alternatives. Graphene, an atomically thin layer of carbon atoms, is regarded as the potential ultimate limit of membrane efficiency for gas separation. Graphene and other two-dimensional materials are a single atom or unit cell thick and represent the absolute lowest mass transfer resistance (or highest throughput) among candidate membrane materials. Hence, this ultimate thinness can yield orders of magnitude higher gas fluxes than those attained using conventional membrane materials. To fulfill this potential, the goal of this project is to experimentally generate nanopores in the graphene layer with controlled size distributions for gas separation. Measurements of gas permeation will be used to gain fundamental understanding about molecular transport through these new types of nanopores using a theoretical and simulation framework. The project will contribute to ongoing educational efforts on the MIT campus, including learning modules for a course called Engineering Nanotechnology, and will engage under-represented student populations at MIT and the Cambridge academic community through high school internship and undergraduate research opportunities. The overarching goal of this proposal is to use a combined approach of experiment, molecular simulation, and theoretical analysis to advance the understanding of transport of gas molecules through molecularly sized nanopores in two-dimensional membranes such as graphene. Firstly, theory and simulations will be used to investigate nanopore formation in graphene and to study the permeation kinetics for different gas species through these nanopores, eventually creating a comprehensive theory to predict gas permeation through a realistic pore size distribution. Secondly, nanoporous graphene membranes will be fabricated, and the gas permeances through these membranes will be measured. Lastly, the formation, modification, and functionalization of the graphene pores will be investigated to further understand gas transport through different graphene pore structures. The combination of theory, molecular simulation, membrane fabrication, characterization, and gas flux measurements will provide the first fundamental links between pore structure and distribution with observed gas permeance, and elucidate the underlying mechanisms of molecular-pore interactions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

分离化学混合物的工业过程对于文明至关重要，包括能源、材料和商品化学品的生产。因此，开发更具选择性和节能的分离工艺是一项重要的技术挑战，有望大幅节省成本以及减少能源消耗和有害排放。大多数工业分离是能源密集型热过程，占世界能源消耗总量的10-15%。基于膜的分离工艺因其降低的能耗和出色的可靠性而成为热分离技术的有吸引力的替代方案。然而，传统气体分离膜的气体通量和选择性之间的权衡历来限制了膜分离装置的整体性能，以及用这些更高效的替代品取代能源密集型工艺的动力。石墨烯是碳原子的原子薄层，被认为是气体分离膜效率的潜在极限。石墨烯和其他二维材料是单个原子或晶胞厚度，代表候选膜材料中绝对最低的传质阻力（或最高的吞吐量）。 因此，这种最终的厚度可以产生比使用传统膜材料获得的气体通量高几个数量级的气体通量。为了实现这一潜力，该项目的目标是通过实验在石墨烯层中生成具有受控尺寸分布的纳米孔，用于气体分离。气体渗透测量将用于通过理论和模拟框架获得对通过这些新型纳米孔的分子传输的基本了解。该项目将为麻省理工学院校园正在进行的教育工作做出贡献，包括工程纳米技术课程的学习模块，并将通过高中实习和本科生研究机会吸引麻省理工学院和剑桥学术界代表性不足的学生群体。该提案的总体目标是使用实验、分子模拟和理论分析相结合的方法来增进对气体分子通过石墨烯等二维膜中分子大小的纳米孔传输的理解。首先，理论和模拟将用于研究石墨烯中纳米孔的形成，并研究不同气体种类通过这些纳米孔的渗透动力学，最终创建一个综合理论来通过实际的孔径分布预测气体渗透。其次，将制造纳米多孔石墨烯膜，并测量通过这些膜的气体渗透率。最后，将研究石墨烯孔的形成、改性和功能化，以进一步了解通过不同石墨烯孔结构的气体传输。理论、分子模拟、膜制造、表征和气体通量测量的结合将提供孔隙结构和分布与观察到的气体渗透性之间的第一个基本联系，并阐明分子-孔隙相互作用的潜在机制。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Direct Chemical Vapor Deposition Synthesis of Porous Single‐Layer Graphene Membranes with High Gas Permeances and Selectivities

• DOI: 10.1002/adma.202104308
• 发表时间: 2021-09
• 期刊: Advanced Materials
• 影响因子: 29.4
• 作者: Zhe Yuan;Guangwei He;S. Faucher;Matthias Kuehne;S. Li;D. Blankschtein;M. Strano

Analytical Prediction of Gas Permeation through Graphene Nanopores of Varying Sizes: Understanding Transitions across Multiple Transport Regimes

• DOI: 10.1021/acsnano.9b05779
• 发表时间: 2019-10-01
• 期刊: ACS NANO
• 影响因子: 17.1
• 作者: Yuan, Zhe;Misra, Rahul Prasanna;Blankschtein, Daniel
• 通讯作者: Blankschtein, Daniel

Gas Separations using Nanoporous Atomically Thin Membranes: Recent Theoretical, Simulation, and Experimental Advances

使用纳米多孔原子薄膜进行气体分离：最新理论、模拟和实验进展

• DOI: 10.1002/adma.202201472
• 发表时间: 2022
• 期刊: Advanced Materials
• 影响因子: 29.4
• 作者: Yuan, Zhe;He, Guangwei;Li, Sylvia Xin;Misra, Rahul Prasanna;Strano, Michael S.;Blankschtein, Daniel
• 通讯作者: Blankschtein, Daniel