Water transport in MOF monoliths under pressure
Year: 2026
Type: preprint
Abstract: Pressurised intrusion into hydrophobic metal-organic frameworks (MOFs) is of considerable interest for energy absorption and fluid transport applications, yet the transport mechanisms in monolithic architectures remain poorly understood. Here, in-situ synchrotron radiographic imaging and powder diffraction have been employed to reveal the mechanism of pressurised water intrusion in ZIF-8 monoliths, through simultaneous visualisation of water transport and monitoring evolution in the crystal structure. The mechanism is dependent on the compactness of the monolith, with denser monoliths exhibiting a distinct edge-to-centre intrusion mechanism, whereas loosely packed monoliths display spatially uniform intrusion across the entire crosssection. Dimensions of the monolith sample also influence the intrusion pressure and extrusion kinetics by altering the transport path length for guest water molecules. These findings provide the first direct experimental evidence of pressure-driven water transport in MOF monoliths and reveal the mechanisms responsible for water intrusion in monoliths with varying dimensions and compacities. Moreover, this is the first study to report simultaneous synchrotron diffraction and imaging at elevated pressures, facilitated by the development of a novel high-pressure sample environment that allows in-situ measurements and has broad potential utility in combined imaging and diffraction studies at elevated pressures.
Source: ChemRxiv
Institutions: University of Birmingham, Diamond Light Source
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7168166326