Functional Materials via Crystal- and Nano-engineering of Metal-Organic Frameworks

技术综述：金属有机骨架(MOF)在过去的十年里引起了人们的极大关注，因为它能够通过对组成单元的修饰来系统地设计MOF中所需的化学和物理性能。在这项提议中，PI将追求两个截然不同的目标--用于储氢的高度稳定和多孔的MOF的晶体工程，以及在核壳纳米结构的模板合成以及生物医学成像和药物输送方面的潜在应用的MOF的纳米工程。在第一个目标中，我们将基于4，4-连接的PTS和4，8-连接的SCU两种拓扑结构，合成一系列坚固的、高度多孔的MOF，并对其吸氢性能进行评估。通过系统地调节桥联配体的大小，？富含芳烃？将得到不同互穿程度的微孔MOF。刚性客体分子将被引入到MOF中，以稳定骨架，增加微孔表面积，并增强MOF与氢的相互作用。在第二个目标中，PI建议继续对纳米级MOF(NMOF)进行基础研究，并探索其在许多领域的潜在应用。皮？S实验室的开创性工作证明了将MOF缩小到纳米级的能力，以生成一类成分、尺寸、尺寸分布和形貌可控的高度可定制的杂化纳米材料。合成方法的进一步完善将允许设计用于潜在的光催化质子还原和水氧化的新型分层组装的核-壳纳米结构，以及用于磁共振成像、计算机断层扫描和药物输送的新型可生物降解和生物相容性纳米材料的合成。这项研究的成功不仅将对可再生和可持续的未来能源战略产生重要影响，而且将为改善人类健康做出积极贡献。非技术综述：DMR建议旨在合理合成一类新的杂化材料，即金属有机骨架(MOF)，在块状和纳米尺度上都是如此。对大块MOF材料的系统工程将允许合成新的储氢材料，这将使用于移动电源的氢基燃料电池技术成为可能。这种储氢材料不仅对国家能源安全至关重要，而且对减少环境污染也具有重要意义。将MOF缩小到纳米级，可以合成一类成分、尺寸、尺寸分布和形貌可控的高度可定制的杂化纳米材料。这种纳米MOF(NMOF)将被用来作为模板合成新型的层次化组装的核壳纳米结构，用于光催化质子还原和水氧化，以及用于合成用于生物传感、生物医学成像和药物输送的新型可生物降解和生物相容性的纳米材料。PI还将积极参与多层次的人才培训，包括高中生、本科生、研究生和博士后研究助理。因此，这项拟议的研究除了对我国S未来的能源技术和医疗保健产生潜在影响外，还将对美国国家科学基金会S促进和整合研究与教育的使命做出重大贡献。

TECHNICAL SUMMARY: Metal-organic frameworks (MOFs) have attracted a great deal of attention over the past decade, due to the ability to systematically engineer desired chemical and physical properties in MOFs via modifications of the constituent building blocks. The PI will pursue two very different objectives in this proposal?crystal engineering of highly stable and porous MOFs for hydrogen storage and nano-engineering of MOFs for potential applications in templated synthesis of core-shell nanostructures and in biomedical imaging and drug delivery. In the first objective, isoreticular families of robust and highly porous MOFs based on both 4,4-connected PtS and 4,8-connected Scu topologies will be synthesized and evaluated for hydrogen uptake. By systematically tuning the size of the bridging ligands, ?aromatics-rich? microporous MOFs with different degrees of interpenetration will be obtained. Rigid guest molecules will be incorporated into MOFs to stabilize the frameworks, to increase microporous surface areas, and to enhance the MOF-hydrogen interactions. In the second objective, the PI proposes to continue fundamental studies on nanoscale MOFs (NMOFs) and explore their potential applications in a number of areas. Pioneering work from the PI?s lab has demonstrated the ability to scale-down MOFs to the nano-regime to generate a new class of highly tailorable hybrid nanomaterials with controllable compositions, sizes, size distributions, and morphologies. Further refinement of the synthetic methodologies will allow the design of novel hierarchically assembled core-shell nanostructures for potential photocatalytic proton reduction and water oxidation and the synthesis of novel biodegradable and biocompatible nanomaterials for magnetic resonance imaging, computed tomography, and drug delivery. The success of this research will not only have important impact on a renewable and sustainable future energy strategy, but also make positive contributions to improved human health. NON-TECHNICAL SUMMARY: This DMR proposal aims at the rational synthesis of a new class of hybrid materials, namely metal-organic frameworks (MOFs), at both the bulk and nanometer scales. Systematic engineering of the bulk MOF materials will allow for the synthesis of new hydrogen storage materials which will enable hydrogen-based fuel cell technology for mobile power sources. Such hydrogen storage materials are of paramount importance not only to the national energy security but also to the reduction of environmental pollution. Scaling down of MOFs to the nanometer regime allows the synthesis of a new class of highly tailorable hybrid nanomaterials with controllable compositions, sizes, size distributions, and morphologies. Such nanoscale MOFs (NMOFs) will be used to template the synthesis of novel hierarchically assembled core-shell nanostructures for photocatalytic proton reduction and water oxidation, as well as for the synthesis of novel biodegradable and biocompatible nanomaterials for biological sensing, biomedical imaging, and drug delivery. The PI will also be actively involved in personnel training at multiple levels, including high school students, undergraduate students, graduate students, and postdoctoral research associates. The proposed research will thus significantly contribute to NSF?s mission on promoting and integrating research and education in addition to its potential impact on our nation?s future energy technologies and health care.