| Apr 01, 2026 |
Weak van der Waals interactions align metal-organic polyhedra into one-dimensional microporous fibrils, enabling flexible aerogels with excellent moldability and paving the way for industrial application of microporous materials.
(Nanowerk News) Porous materials are widely used for gas storage, separation, catalysis, and environmental purification. Their functionality arises from nanoscale pores that allow molecules to be selectively captured or transported. However, most porous materials, such as metal-organic frameworks, rely on rigid three-dimensional networks formed by strong chemical bonds, which often make them mechanically brittle and difficult to process into practical shapes.
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A research team led by Professor Shuhei Furukawa at the Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, has developed a new type of microporous aerogel that overcomes these limitations. Their study (Journal of the American Chemical Society, “One-Dimensional van der Waals Porous Fibrils Assembled from Metal–Organic Polyhedra”) demonstrates a strategy to assemble metal–organic polyhedra (MOPs) into hierarchically ordered one-dimensional porous fibrils using weak van der Waals interactions.
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| Schematic illustration of porous fibrils assembled from metal–organic polyhedra (MOPs) and the resulting flexible porous aerogel. (Image: Kyoto University)
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Unlike conventional porous frameworks constructed through strong chemical bonds, the newly developed fibrils are held together by reversible van der Waals interactions between MOP molecules. Thanks to the weak nature of these interactions, the molecular assemblies can reversibly associate and dissociate with minimal energy input, exhibiting thixotropic behavior. This feature allows the material to be easily shaped using molds, providing a high degree of processability that is rarely achieved in conventional microporous materials.
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Mechanical testing revealed that the newly synthesized aerogels, assembled from entangled fibrils, can withstand very large compressive deformation without any catastrophic fracture.
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The exceptional mechanical deformability arises from their fibrillar morphology, which allows the structure to dissipate applied stress. The fibrillar aerogel showed microporosity originating from the intrinsic pores of the MOP molecules. This result contrasts sharply with conventional microporous crystals, where rigid three-dimensional frameworks often fracture under small mechanical stress.
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“Our design demonstrates that high crystallinity supported by a rigid three-dimensional network is no longer necessary to construct microporous materials,” says Professor Shuhei Furukawa. “By controlling how molecular building blocks connect to each other, we can create porous materials that are both flexible and highly processable.”
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The concept introduced in this study could be extended to a wide range of molecular building blocks beyond MOPs. The researchers expect that this design strategy will provide a pathway to developing new porous materials with excellent mechanical properties suitable for industrial applications.
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