CAREER: Elucidating the Synergistic Effects of Composition, Porosity and Structural Rigidity on Mechanics of Metallic Organic Frameworks

该学院早期职业发展奖将支持揭示玻璃金属有机骨架(GMOF)的组成、孔隙率、原子结构和机械行为之间的基本关系的研究。GMOF是一种多孔杂化材料，通常由金属离子组成，通过有机连接物(配体)连接起来，形成一个巨大的强化网络。转基因生物材料的一个主要优点是，它们可以批量生产，形状多样，可用于各种应用。该奖项将通过对这些吸收材料的压缩和剪切行为的实验理解来促进科学进步，这对它们在工业二氧化碳捕获、分离和储存应用中的使用至关重要。这里开发的技术和测试是通用的，也将增加对特性类似于GMOF的材料中的机械响应的理解。该项目还将通过研究机会和创新的教育材料为从高中到研究生院的学生提供培训。将特别努力招收STEM的美洲原住民学生。该奖项的目的是了解GMOF中的以下现象：(1)非弹性耗散过程的性质，(2)结构顺序、组成和密度的潜在独特影响，以及(3)能量松弛对适应接触载荷能力的影响。综合实验-计算方法将从基于原子力显微镜的压痕和划痕测试开始，以量化小规模的压缩和剪切响应。其次，不同孔隙率的影响将通过测试与GMOF具有相似孔径和孔径分布的构造硅酸盐沸石来确定。第三，为了将力学性能与原子结构的刚性联系起来，将结合拓扑约束理论(TCT)进行MD模拟。最后，将对GMOF的整体力学行为进行实验表征，以关联较小规模的非弹性耗散机制对宏观弹性/强度属性和非弹性行为的影响。该奖项反映了NSF的法定使命，并已通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) Award will support research to uncover the fundamental relationships between composition, porosity, atomic structure, and the mechanical behavior of glassy metallic organic frameworks (gMOFs). gMOFs are porous hybrid materials, often consisting of metallic ions, connected by organic linkers (ligands), to form a vast reinforced network. A major advantage of gMOFs is that they can be made in bulk, in diverse shapes, for a variety of applications. This award will promote the progress of science by focusing on the experimental understanding of the compression and shear behaviors of these absorbent materials, which is crucial for their use in industrial CO2 capture, separation, and storage applications. The techniques and testing developed herein are generic and will also increase the understanding of mechanical responses in materials similar in characteristics to gMOFs. This project will also provide training to students from high school through graduate college via research opportunities and innovative educational material. Special efforts will be made to recruit Native American students in STEM. The objective of this award is to understand the following phenomena in gMOFs: (1) the nature of inelastic dissipation processes, (2) the underlying distinct influences of structural order, composition, and density, and (3) the influence of energy relaxation on the ability to accommodate contact loads. The integrated experimental-computational approach will start with AFM-based indentation and scratch testing to quantify compression and shear responses at small scales. Second, the effects of different porosities will be determined by testing tectosilicate zeolites that contain similar pore sizes and pore size distributions compared to the gMOFs. Third, to relate the mechanical properties to the rigidity of the atomic structure, MD simulations coupled with topological constraint theory (TCT) will be performed. Finally, bulk mechanical behavior of the gMOFs will be experimentally characterized to correlate the influence of smaller scale inelastic dissipation mechanisms on macroscale elastic/strength properties and inelastic behaviors.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.