NSF-DFG Confine: Diffusion of Water Confined in Patterned Hydrophilic-Hydrophobic Nanopores

NSF-DFG 限制：图案化亲水-疏水纳米孔中限制的水的扩散

• 批准号: 2223442
• 负责人: Laura Gagliardi
• 金额: $ 60万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-10-01 至 2025-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2223442&HistoricalAwards=false
• 关键词: NSF; DFG; Confine; Diffusion; Water

With support from the Chemical Structure, Dynamics and Mechanisms-A (CSDM-A) Program in the Division of Chemistry, Professors Laura Gagliardi of the University of Chicago and Omar Yaghi of the University of California at Berkeley are combining advanced molecular simulation and chemical analysis tools such as nuclear magnetic resonance (NMR) to explore and characterize the motion of water molecules inside metal-organic frameworks (MOFs). Water is essential to life and understanding how water molecules move in confined spaces is of fundamental interest. This research focuses on MOFs with well-defined patterns of alternating water attracting (hydrophilic) and water repelling (hydrophobic) grid-like tiled regions. This project seeks to reveal for the first time the molecular level details of the diffusion of water within this patterned space and the interplay between the hydrophilic and hydrophobic regions. Professor Gagliardi, her student and a collaborator in Germany (Professor Joachim Sauer, Humboldt University) will perform quantum mechanical calculations to predict water-MOF interactions, and Professor Yaghi and his student will characterize the water-MOF interactions with NMR spectroscopic techniques. The discoveries of this project could lead to a variety of useful applications of MOF materials, including liquid and gas separations and purification, water harvesting, and CO2 capture. In addition to formal research training activities, the Gagliardi group also seeks to inspire future generations of internationally aware scientists through the Chicago chapter of Expanding Your Horizons. This collaborative project will provide the students involved with a rich interdisciplinary and international experience. Professor Gagliardi and her student compute chemically accurate adsorption constants for water molecules on a lattice of adsorption sites from ab initio free energies; they also compute chemically accurate diffusion rate constants for jumps of water molecules between adsorption sites using ab initio transition state theory. To define elementary diffusion steps, they define adsorption cells and consider all possible jump pathways between sites in neighbored cells in all crystallographic directions. Finally, they predict adsorption isotherms and diffusivities as a function of loading using Grand Canonical Monte Carlo (GCMC) and kinetic Monte Carlo (kMC) simulation, respectively, on a lattice of sites. Professor Sauer is providing ab initio-calculated potential energy surfaces to augment the accuracy of the GCMC and kMC simulations. Professor Yaghi and his student will synthesize MOF materials and study the water self-diffusion at different water loadings in the MOF pores using pulsed magnetic field gradient NMR measurements. This should allow for a direct comparison with the predicted intrapore diffusion constants. Additionally, they will employ quasi-elastic neutron scattering (QENS) to gain more insight about the water mobility in the nanopores at different loadings. Importantly, QENS would provide exclusive information about the diffusion model and mechanism in the MOF pores.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.

借助化学结构，动力学和机制-A（CSDM-A）计划，芝加哥大学的Laura Gagliardi教授和加利福尼亚大学伯克利大学的Omar Yaghi结合了高级分子模拟和化学分析工具，例如核磁共振（NMR）的化学分析工具（NMR），以探索核磁共振（NMR）。 （MOF）。水对于生命至关重要，并了解水分子在狭窄的空间中的移动是基本的兴趣。这项研究的重点是具有明确定义的交替水吸引（亲水）和排水（疏水）网格样瓷砖区域的MOF。 该项目试图首次揭示水在该图案空间内的扩散以及亲水和疏水区之间的相互作用的分子水平细节。 Gagliardi教授，她的学生兼德国合作者（洪堡大学Joachim Sauer教授）将执行量子机械计算以预测水 - 莫夫的相互作用，Yaghi教授和他的学生将表征与NMR光谱技术的水 - 水流相互作用。该项目的发现可能会导致MOF材料的各种有用的应用，包括液体和气体分离以及纯化，收集水和CO2捕获。 除了正式的研究培训活动外，Gagliardi小组还试图通过芝加哥章节来激发未来的国际知识科学家，以扩大您的视野。这个协作项目将为参与的学生提供丰富的跨学科和国际经验。 Gagliardi教授和她的学生在从初始自由能量的吸附位点上计算水分子的化学精确吸附常数；他们还使用从头开始过渡状态理论计算了化学精确的扩散速率常数，用于在吸附位点之间的水分子跳跃。为了定义基本扩散步骤，它们定义了吸附细胞，并考虑了所有晶体学方向的邻居细胞中位置之间的所有可能的跳跃路径。最后，他们分别预测吸附等温线和扩散率是使用大规范的蒙特卡洛（GCMC）和动力学蒙特卡洛（KMC）模拟的载荷的函数。 Sauer教授正在提供从头开始计算的势能表面，以提高GCMC和KMC模拟的准确性。 Yaghi教授和他的学生将使用脉冲磁场梯度NMR测量值合成MOF材料，并研究MOF孔中不同水载的水自扩散。这应该可以与预测的肠内扩散常数进行直接比较。此外，他们将采用准弹性中子散射（Qens），以更多地了解不同载荷下纳米孔中的水迁移率。重要的是，卫生部将提供有关MOF孔中扩散模型和机制的独家信息。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响审查标准通过评估来支持的。

项目成果

A Porous Crystalline Nitrone‐Linked Covalent Organic Framework**

多孔结晶硝酮 - 连接共价有机框架**

• DOI: 10.1002/anie.202307674
• 发表时间: 2023
• 期刊: Angewandte Chemie International Edition
• 作者: Kurandina, Daria;Huang, Banruo;Xu, Wentao;Hanikel, Nikita;Darù, Andrea;Stroscio, Gautam D.;Wang, Kaiyu;Gagliardi, Laura;Toste, F. Dean;Yaghi, Omar M.
• 通讯作者: Yaghi, Omar M.