A team of scientists from France, UK and the ESRF have recently discovered an unprecedented giant and reversible swelling of nanoporous materials with exceptional properties: huge flexibility and profound selectivity. They publish their results in Science this week.
Porous hybrid solids are the new materials that could make the world more environmentally friendly. The team from Institut Lavoisier at University of Versailles have developed metal-organic three-dimensional structures with cages and channels (known as MIL, for Material Institut Lavoisier). These compounds contain metal ions (in this case chromium and iron), with organic linkers and are very flexible, and hence, can change shape very easily. They can open up or close down to external factors such as pressure, temperature, light or influence of gases and solvents.
The French researchers, in collaboration with the staff of the Swiss-Norwegian experimental station (called beamline) at the ESRF, have tracked, for the first time, a reversible giant increase in volume of these solids. It ranges from 85% of their size to up the unprecedented 230%. Such a large expansion in crystalline materials has not been observed before. This reversible “breathing” action is similar to the lungs’ function in humans: they grow in size when inhaling and go back to their original size when exhaling. The lungs expand, however, by only around 40%.
The huge swelling effect has been achieved in a simple way: MIL materials were immersed into solvents, and their cavities were filled and thus opened by entering solvent molecules. This made the structures grow, without breaking bonds and retaining the crystallinity of the materials. This process was monitored at the ESRF, using high-quality synchrotron radiation and the experimental results were combined with computer chemistry simulations.
This process can reversed by heating the solvated form the dry form is recovered. In this form, the material exhibited closed pores with almost no accessible porosity. Surprisingly, the same team published a paper last autumn where they showed that some gas molecules can close, but not open, the pores upon absorption. Moreover, the closed hydrated form demonstrates a remarkable selectivity in absorption of polar and nonpolar gases.
The next step for the team now is to investigate how hydrogen or green-house gases can be stored in these kinds of materials. This may open a door to ecological applications such as hydrogen cars or the capture of carbon dioxide in the near future.
Montserrat Capellas | alfa
Glass's off-kilter harmonies
18.01.2017 | University of Texas at Austin, Texas Advanced Computing Center
Explaining how 2-D materials break at the atomic level
18.01.2017 | Institute for Basic Science
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
19.01.2017 | Earth Sciences
19.01.2017 | Life Sciences
19.01.2017 | Physics and Astronomy