Synthetic Control over MOF Particle Growth and Surface Chemistry

非技术概述基于金属-有机骨架（MOF）的膜，其为三维（3-D）有机/无机化合物，由于其优异的可调性和合成多样性，吸引了工业石油精炼和气体分离的强烈兴趣。然而，为了使MOFs在工业领域获得广泛的吸引力和应用，研究人员将需要超越3-D MOFs并开发新型的MOFs纳米颗粒，因为它们表现出上级分离性能并产生具有上级稳定性的膜。在过去的二十年里，MOF的散装粉末占据了学术MOF研究的焦点，但最近的注意力已经转向制备具有精确控制粒度的MOF纳米颗粒和聚合物复合材料。尽管初步证明了MOF纳米颗粒的巨大潜力，但关键的基本问题仍然是实现对MOF颗粒组成的可再现控制以及了解颗粒大小和组成如何影响膜性能。通过这个项目，由NSF材料研究部的固态和材料化学计划支持，俄勒冈州大学的Carl Brozek教授和他的研究小组将研究控制MOF纳米晶体精确尺寸和组成的化学原理。机械生长模型将在为其他类型的材料建立的生长模型的背景下开发，以便这些结果通知材料化学的广泛领域。同样，本提案中所追求的合成技术将通过概述对多种尺寸范围内的材料进行分子控制的基本工具，影响MOF颗粒以外的材料设计。所提出的研究实际上与社会相关，因为对MOF尺寸的精确控制将为工业改进气体分离膜开辟新的前沿，并有机会将MOF应用性能提升到实际相关。该项目由NSF材料研究部的固态和材料化学计划支持，将研究金属有机框架（MOF）颗粒的基本生长机制，开发控制颗粒表面化学的方法，以提高其胶体稳定性并与聚合物复合材料界面连接，了解尺寸和表面组成对分子和电荷传输特性的影响。要实现这一目标，需要对决定颗粒尺寸、缺陷掺入和表面功能化的参数进行基本研究。深入了解控制prenucleation晶体生长的材料一般，可重复合成的MOF基异质结构复合材料，并提高实际相关性的MOF材料将导致从这项研究。该提案的更广泛影响包括：1）将这些研究目标纳入教育推广计划，向服务不足的学生传达碳捕获技术的科学，2）促进跨学科培训计划，将化学与建筑专业的学生配对设计空气净化模块，3）赞助基于MOF的碳捕获的行业学术研讨会系列，以及4）实施一个关于设计推广计划的教学课程，该课程全年为俄勒冈州大学（UO）化学博士生提供。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical SummaryMembranes based on metal-organic frameworks (MOFs), which are three-dimensional (3-D) organic/inorganic compounds, attract intense interest for industrial petroleum refining and gas separations due to their exceptional tunability and synthetic diversity. For MOFs to reach widespread attraction and implementation in the industrial sector, however, researchers will be required to go beyond 3-D MOFs and develop new types of MOF nanoparticles, as they exhibit superior separation performance and generate membranes with superior stability. For the past two decades, bulk powders of MOFs occupied the focus of academic MOF research, but very recent attention has turned to preparing MOF nanoparticles and polymer composites with precise control of particle sizes. Despite preliminary demonstrations of the great potential of MOF nanoparticles, key fundamental questions remain for achieving reproducible control over MOF particle composition and for understanding how particle size and composition impact membrane performance. With this project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, Prof. Carl Brozek at the University of Oregon and his research group will investigate the chemical principles that control the precise sizes and compositions of MOF nanocrystals. Mechanistic growth models will be developed in the context of growth models established for other classes of materials so that these results inform the broad field of materials chemistry. Similarly, the synthetic techniques pursued in this proposal will influence materials design beyond MOF particles, by outlining fundamental tools for molecular control over materials across multiple size regimes. The proposed research is practically relevant to society because precise control over MOF nanocrystal sizes will open new frontiers in improved gas separation membranes for industry and the opportunity for elevating MOF application performance to becoming practically relevant. Technical Summary This project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, will investigate the fundamental growth mechanisms of metal-organic framework (MOF) particles, develop methods to control particle surface chemistry for enhancing their colloidal stability and interfacing with polymer composites, and understand the impact of size and surface composition on molecular- and charge-transport properties. Tackling this goal will require basic investigation into the parameters that dictate particle sizes, defect incorporation, and surface functionalization. Insight into controlling prenucleation crystal growth of materials in general, reproducible synthesis of MOF-based heterostructure composites, and improving the practical relevance of MOF materials will result from this research. Broader impacts of this proposal include 1) integrating these research aims into educational outreach initiatives that communicate the science of carbon capture technology to underserved students, 2) fostering interdisciplinary training programs that pairs chemistry with architecture students to design air-purification modules, 3) sponsoring industry-academia seminar series on MOF-based carbon-capture, and 4) implementing a teaching course on designing outreach initiative offered year-round to University of Oregon (UO) chemistry PhD students.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.