Science researchers from the University of Versailles (France), in collaboration with the ID31 beam line at the European Synchrotron Radiation Facility (ESRF), report their progress in the design and characterisation of microporous materials. The combination of adept chemistry and computational design made possible the synthesis of a new material, named MIL-101 by its originators, (where MIL stands for Matériaux de l’Institut Lavoisier), with very large internal pores (ø~3.4nm) and surface area (5,900 m2.g-1). The new, crystalline material is representative of a class of compounds, known as metal organic framework materials, (MOFs), with potential applications in many fields including chemical separation, heterogeneous catalysis and gas storage. Confirmation of the structure of the new material exploited the intense X-ray beams at the ESRF.
Starting from simple assemblies and linking units, larger and larger building blocks combine to form crystalline nanoporous materials with more surface area than zeolites. The Zeotype architecture of MIL-101 displays mesoporous cages with diameters of 29 Å (green) and 34 Å (red), featuring 12 Å pentagonal and 15 Å hexagonal openings. Credits: Science
Porous materials with large, regular, accessible cages and tunnels are increasingly in demand for many applications including chemical separation or purification, catalysis, molecular sensors, electronics and gas storage. Depending on their structure and pore size, these materials allow molecules of only certain shapes and sizes to enter the pores, a property known as shape selectivity. The environment within the pores can be very different to that outside, thus promoting chemical reactions that do not occur in the bulk material. Another prospective use is as templates for forming calibrated, monodisperse nanomaterials. In this respect, the larger the pores, the wider the range of reactants that can be manipulated or stored.
Férey and co-workers’ strategy combined three main ideas. First, discrete multi-atom building units were designed and generated in solution (Fig. 1). Second, with the aim of producing a compound with large pores, the building units were combined to produce larger units. For MIL-101 the key building unit is a supercluster of four smaller clusters linked by difunctional organic components to make a large tetrahedral assembly. The third idea involves being sure of what you’ve actually made, i.e. how to determine the structure of the new material. It is well known that it becomes increasingly difficult to grow highly diffracting single crystals as structures grow larger. When single crystals are unavailable, powder diffraction can provide sufficient information for structure solution. Based on their understanding of the ways the building units might combine, possible structural models were predicted and assessed via a computational strategy that calculated their relative stability. Favourable solutions were then compared with the high quality powder diffraction data collected from MIL-101 at ESRF. Once a good match between the predicted and measured powder patterns was seen, the researchers could be sure of the nature of their new material.
Montserrat Capellas | alfa
New design improves performance of flexible wearable electronics
23.06.2017 | North Carolina State University
Plant inspiration could lead to flexible electronics
22.06.2017 | American Chemical Society
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology