A research team led by Patrick Huber (DESY and TU Hamburg) has discovered a surprising behavior in a nanoporous silicate glass: Instead of the expected shrinkage due to the negative pressure generated by the evaporation of water, the material expanded slightly – an effect that is due to a reduction in the interfacial tension at the pore walls. This causes a stronger expansion than the suction pressure causes a compression. This phenomenon was confirmed with the help of sensitive measurements and computer simulations. An “artificial tree” made of this material could transport water over several hundred meters – an achievement that far surpasses that of natural trees.
The discovery opens up numerous possible applications. For example, the filling level of liquids in opaque materials could be monitored by simple length measurements, which is relevant for batteries, supercapacitors and filter membranes. The process is also suitable for precise humidity detectors or for energy generation, for example by alternately wetting and drying nanoporous materials. The research team is already working on extending the method to other materials such as nanoporous carbon and electrolytes. Further details on the research results can be found in the original DESY press release: Expanding instead of Contracting.
Original publication: Deformation dynamics of nanopores upon water imbibition, Juan Sanchez, Lars Dammann, Laura Gallardo, Zhuoqing Lia, Michael Fröba, Robert H. Meißner, Howard A. Stone, Patrick Huber, “PNAS”, 2024, DOI:10.1073/pnas.2318386121
