High-rate nanofluidic energy absorption in porous zeolitic frameworks

• Published in: Nature materials Vol. 20; no. 7; pp. 1015 - 1023
• Main Authors: Sun, Yueting, Rogge, Sven M. J., Lamaire, Aran, Vandenbrande, Steven, Wieme, Jelle, Siviour, Clive R., Van Speybroeck, Veronique, Tan, Jin-Chong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.07.2021; Nature Publishing Group
• Subjects: 119/118; 639/166/988; 639/301/1005/190; 639/301/1034/1035; 639/301/299/1013; 639/301/357/537; Absorbers; Absorption; Biomaterials; Chemistry and Materials Science; Condensed Matter Physics; Energy; Energy absorption; Energy storage; Extrusion rate; Fluidics; Hydrophobic and Hydrophilic Interactions; Intrusion; Materials Science; Metal-organic frameworks; Microfluidic Analytical Techniques - methods; Molecular Dynamics Simulation; Nanofluids; Nanotechnology; Optical and Electronic Materials; Porosity; Porous materials; Storage capacity; Water; Water infiltration; Water transport; Zeolites; Zeolites - chemistry
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/s41563-021-00977-6

Optimal mechanical impact absorbers are reusable and exhibit high specific energy absorption. The forced intrusion of liquid water in hydrophobic nanoporous materials, such as zeolitic imidazolate frameworks (ZIFs), presents an attractive pathway to engineer such systems. However, to harness their full potential, it is crucial to understand the underlying water intrusion and extrusion mechanisms under realistic, high-rate deformation conditions. Here, we report a critical increase of the energy absorption capacity of confined water-ZIF systems at elevated strain rates. Starting from ZIF-8 as proof-of-concept, we demonstrate that this attractive rate dependence is generally applicable to cage-type ZIFs but disappears for channel-containing zeolites. Molecular simulations reveal that this phenomenon originates from the intrinsic nanosecond timescale needed for critical-sized water clusters to nucleate inside the nanocages, expediting water transport through the framework. Harnessing this fundamental understanding, design rules are formulated to construct effective, tailorable and reusable impact energy absorbers for challenging new applications. Porous materials can absorb energy by water infiltration, but studies at industrially relevant high-rate intrusions are rare. Here, high-rate experiments are performed on ZIFs showing high energy storage capacity, while molecular simulations allow design rules to be formulated for absorption materials.