Designing Chemistry and Morphology in Metal-Organic Framework Gels, Liquids and Glasses

金属有机骨架（mof）是由无机节点组成的三维结构，由有机连接剂连接。不同的元素或功能可以轻松地结合到大量的纳米级结构中，这导致了大量化合物的存在。已经报道了超过60,000种晶体结构，它们可以“调谐”以对预先确定的目标客体分子表现出特殊的选择性。来自西北大学和贝尔法斯特女王大学的两家公司的两种产品已在有毒气体储存和水果包装领域实现商业化。此外，它们在高选择性二氧化碳捕获、药物输送、化学传感、有毒气体分离和有害废物储存应用方面的应用已经提出了巨大的社会和经济效益，尽管尚未实现。这在一定程度上是由于化学合成方面取得的重大进展与对其物理性质的研究缺乏之间的差距。因此，令人非常惊讶的是，即使是最基本的物理性质，物质的状态，也代表了MOF领域中研究最不足的领域之一。因此，本提案旨在解决这种对有序的结晶固体畴的偏见，考虑到该领域的研究投入以及非晶畴的机械稳定性与mof提供的化学机会相结合的潜在好处，这一点至关重要。最近MOF家族的玻璃形成能力的发现提供了一个诱人的前景，通过首先调整母体晶体框架的化学性质，在随后的熔化和液体淬火之前，精确地设计功能性玻璃。以这种方式将功能从水晶转移到玻璃，将使下一代功能玻璃的生产成为可能。这些材料将处于使mof摆脱目前对晶体多孔状态的关注的努力的最前沿。项目期间将生产两类新型功能性mof玻璃；(1)用于分离的多孔MOF玻璃和(2)用于高级光学应用的手性MOF玻璃。就前者而言，考虑到目前的混合基质膜存在化学相容性问题和活性成分减少，用于气体分离的多孔mof -玻璃或mof -玻璃复合膜的开发将证明是该领域的重大进步。此外，还将研究mof在液相中的反应，并研究由此产生的多组分玻璃的结构和性能。mof的“软”性质也导致一些框架在后处理过程（例如烧结、球磨、球团化）中结构崩溃，这些过程用于将纳米晶体粉末转化为工业上可用的形态。因此，从微晶粉末中开发各种形态（即薄膜，珠状和自支撑，无粘合剂的膜）对于该领域的应用是绝对必要的。专注于从根本上扩展我们对该领域的基本理解，同时弥合基础科学与工业相关性之间的差距，该项目本质上是高度跨学科的。因此，本建议的总体目标是：(i)创造新的多孔和手性MOF玻璃；（ii）通过结合晶体MOF和玻璃状MOF来创造用于分离的新复合材料；（iii）为两种MOF液体的反应生成二元相图并分析形成的产物；（iv）在该小组之前的工作中产生的交联不稳定的MOF球体，并将该方法扩展到另一个MOF家族。

Metal-organic frameworks (MOFs) are three-dimensional structures composed of inorganic nodes, connected by organic linkers. The ease at which different elements or functionalities can be incorporated into a plethora of nanoscopic architectures has led to the population of an enormous class of compounds. Over 60,000 crystalline structures have been reported, which can be 'tuned' to exhibit exceptional selectivity for pre-determined target guest molecules. Two products, from companies span out of Northwestern and Queen's University Belfast, have been commercialised, in the areas of toxic gas storage and fruit packaging. Furthermore, huge societal and economic benefits from their use in highly selective CO2 capture, drug delivery, chemical sensing, toxic gas separations and harmful waste storage applications have been proposed, though not delivered. This is partly due to the gap between the significant strides made in chemical synthesis, and a dearth of work on their physical properties.It is therefore highly surprising that even the most basic of all physical properties, the state of matter, represents one of the most under-researched areas in the MOF field. This proposal hence aims at addressing this bias towards the ordered, crystalline solid domain, which is vital given the research invested into the field and the potential benefits from the combination of the mechanical stability of the amorphous domain, with the chemical opportunities afforded by MOFs.The recent discovery of the glass-forming ability of the MOF family offers the tantalising prospect of accurately designing functional glasses by first tuning the chemical properties of the parent crystalline framework, prior to subsequent melting and liquid quenching. The transfer of functionality from crystal to glass in this manner will enable the next generation of a plethora of functional glasses to be produced. Such materials will lie at the forefront of efforts to move MOFs away from the current focus on the crystalline porous state. Two new classes of functional MOF-glasses will be produced in the course of the project; (i) porous MOF-glasses for separations and (ii) chiral MOF glasses for advanced optical applications. With respect to the former, the development of porous MOF-glasses or MOF-glass composite membranes for gas separations would prove a significant advancement in the field, given the current mixed matrix membranes suffer from chemical compatibility problems and a reduction in active component. In addition, reactions between MOFs in the liquid phase will be studied, and the structure and properties of the resultant multicomponent glasses produced investigated.The 'soft' nature of MOFs also leads to the structural collapse of some frameworks during the post-processing processes (e.g. sintering, ball-milling, pelletisation) used to convert nano-crystalline powders to industrially useable morphologies. The development of a variety of morphologies (i.e. thin films, beads, and self-supporting, binder-free membranes from microcrystalline powders is therefore absolutely essential for the field to move forwards to application. Concentrating on both fundamentally expanding our basic understanding of the field and at the same time bridging the gap between basic science and industrial relevance, this project is highly interdisciplinary in nature. The overarching aims of this proposal are thus to; (i) create new porous and chiral MOF-glasses (ii) create new composite materials for separation by combining crystalline MOFs and their glassy counterparts, (iii) produce a binary phase diagram for the reaction of two MOF liquids and analyse the products formed and (iv) cross-link unstable MOF spheres produced in previous work by the group, and extend the methodology to another MOF family.