EAGER: Nuclear Transmutation in Metal Organic Frameworks through Neutron Absorption

在化学系化学合成项目的支持下，华盛顿州立大学的张强和Zachariah Heiden致力于开发一种创新的方法，通过核嬗变在金属-有机框架中创造独特的混合金属结构，并研究其在辐照下的稳定性。金属-有机框架是通过将金属离子与有机分子连接，形成一维、二维或三维结构而制成的。这种结构可以看作是带有孔或口袋的微观支架。这些口袋可以达到结构体积的90%，这意味着它们像海绵一样具有高度多孔性。传统的方法很难用特定的混合金属物种来创造这些结构，但是这种新的嬗变方法可能是克服这一重大限制的关键。如果成功，这种方法产生的材料有望具有独特的性能，可能会在传感器技术、催化剂开发和可以吸收特定物质的材料等各个领域带来重大进步。这个项目的一个重要方面是调查这些材料在极端条件下的表现。这些知识可以帮助创造出能够承受恶劣环境的材料，比如外层空间，或者可以改善核废料管理。该项目将为学生，特别是那些来自弱势群体的学生提供独特的机会，在博士的指导下，获得多孔材料合成和核反应堆操作方面的实践培训和经验。张和海登。本研究旨在利用金属有机骨架（mof）内的核嬗变引入二次金属中心，并研究其在中子辐照下的稳定性。这些新材料在中子辐射下的弹性将根据其元素组成、结构和中子剂量进行严格评估。活化同位素的水平是由中子剂量决定的，在监测衰变过程的同时，可以通过调节中子辐照通量来控制。将这些二次金属中心掺入MOF结构的预期结果是目标MOF的稳定性和电子特性都发生了重大变化。例如，在钒MOFs中引入铬有望提高材料的稳定性。由于Cr离子的大小、酸度和氧化还原化学性质与V离子不同，钒MOF中铬离子的形成也有望改变MOF的电子性能。该项目将探索这些材料在中子通量下的配位化学和结构动力学。这个高风险/高回报的项目有潜力发现开发具有增强性能和功能的先进材料的创新方法，从而有可能为材料科学领域做出重大贡献。该奖项反映了美国国家科学基金会的法定使命，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。

With the support of the Chemical Synthesis program in the Division of Chemistry, Qiang Zhang and Zachariah Heiden of Washington State University aim to develop an innovative way to create unique mixed-metal structures in metal-organic frameworks through nuclear transmutation and study their stability under irradiation. Metal-organic frameworks are made by linking metal ions with organic molecules to form structures that can be one, two, or three-dimensional in nature. Such structures can be considered as microscopic scaffolds with holes or pockets. These pockets can be up to 90% of the volume of the structures, which means they are highly porous like a sponge. Traditional methods have struggled to create these structures with specific mixed metal species, but this new transmutation approach could be the key to overcoming this significant limitation. If successful, the materials resulting from this approach are expected to have unique properties that could potentially bring significant advances to various fields such as sensor technology, catalyst development, and materials that can absorb specific substances. A vital aspect of this project is the investigation into how these materials behave under extreme conditions. This knowledge could help in creating materials that can withstand harsh environments such as outer space, or that can improve nuclear waste management. The project will offer unique opportunities for students, particularly those from underrepresented groups, to get hands-on training and experience in porous materials synthesis and nuclear reactor operation under the guidance of Drs. Zhang and Heiden.The funded research aims to apply nuclear transmutation within metal-organic frameworks (MOFs) to introduce secondary metal centers and study their stability under neutron irradiation. The resilience of these new materials under neutron radiation will be rigorously assessed based on their elemental composition, structure, and neutron dose. The level of activated isotopes, which is determined by the neutron dosage, can be controlled by adjusting the neutron irradiation flux while monitoring decay processes. The anticipated consequence of incorporating these secondary metal centers into the MOF structure is a significant alteration in both the stability and electronic properties of the target MOFs. For instance, the introduction of chromium into vanadium MOFs is expected to enhance material stability. The formation of chromium within vanadium MOFs is also expected to alter the electronic properties of the MOF, as the size, acidity and redox chemistry of Cr ions are different from those of the V ions. The project will probe the coordination chemistry and structural dynamics of these materials under neutron flux. This high risk/high potential reward project has the potential to uncover innovative methodologies for developing advanced materials with enhanced properties and functionalities, thereby potentially making a significant contribution to the field of materials science.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.