AMICI: Amorphous Microstructure Imaging at Composite Interfaces in Metal-Organic Frameworks

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Reducing emissions requires advances in separations (replace energy-intensive distillations), fuel cells (use robust, low-cost membranes), and high-efficiency lighting (encapsulate halide perovskites), all relying on efficient control of chemical transport. Metal-organic frameworks (MOFs), consisting of metal nodes linked by organic molecules in characteristically porous networks, are poised to accelerate energy savings if we can harness their structural and chemical selectivity. Yet device integration is challenging. Most often prepared as crystalline powders, fusing MOFs with polymers or glasses made from other MOFs creates device-compatible forms. In turn, interfacial interactions boost gas uptake, proton conductivity, and luminescence. However, the defining non-periodic structures remain unresolved. This project will unveil the microscopic structural variety in MOF composites by determining the atomic structure of amorphous components, distortions in crystals, and changes at interfaces.My ambitious research programme will build a nanoscale version of the technique known as electron pair distribution function analysis for MOF/MOF, MOF/polymer, and MOF/perovskite composites using scanning transmission electron microscopy. Now uniting cryogenic, low-dose microscopy and precession electron optics, I will make direct microscopic observations to answer questions on how MOFs melt and form glasses, how guest molecules move through MOFs, and how molecules traverse MOF/polymer membranes. Together with dynamic and multi-scale microscopies, I will combine these tools to track water transport in a model fuel cell membrane. Only through developing nanometre-resolved imaging of amorphous microstructure (domain size, shape, composition, and atomic structure descriptors across interfaces) will it be possible to determine precise structure-function relationships and rationally design host-guest and matrix-filler interactions to realise the potential of MOF technologies.