For the first time they used mechanical forces to control catalytic activity – one of the most fundamental concepts in chemistry. This allowed them to initiate chemical reactions with mechanical force.
This discovery paves the way to developing materials capable of repairing themselves under the influence of mechanical tension. The results of their research will be published online on 6 April 2009 in the new international journal Nature Chemistry.
The research team (Dr. Alessio Piermattei, Dr. Karthik Sivasubramanian and Dr. Rint Sijbesma) of the Institute for Complex Molecular Systems (ICMS) and the Department of Chemical Engineering and Chemistry, both at TU/e, is the first to have demonstrated that a catalyst can be switched from a dormant to an active state (see illustration) by pulling on a polymer chain, a "molecular ripcord." The researchers were able to use this catalyst to initiate a variety of chemical reactions, including polymerizations (formation of polymer chains from small molecular building blocks called monomers).
This discovery paves the way to creating self-repairing materials that strengthen under the influence of mechanical stress. If a material were to tear, for example, this would simultaneously break the metal complex in half, thereby activating the catalyst, and the material would be instantly repaired.
This work will also lead to research into other applications in which it should be possible to turn chemical reactions on and off as desired. Potential applications include the injection molding of plastic objects, where the technique could be used to simplify processing, or microscale chemical synthesis.
How does it work; weakest link
The researchers packed a catalytically active metal ion completely in using two molecular caps (ligands). They attached two polymer chains to these caps, creating a long chain with a metal complex in the center. These complexes were dissolved in a liquid that was irradiated with ultrasound, causing bubbles to form in the liquid. When these bubbles imploded, they created an extremely strong current that stretched the chains and ultimately broke its weakest link – the metal complex – in two. The cap on one end was now broken off from the active metal ion, which allowed the metal ion to become catalytically active. In other words, it could now accelerate chemical reactions.
This research was sponsored with an ECHO project subsidy from NWO (Netherlands Organization for Scientific Research). The subsidy, in the amount of 240,000 euros, is intended to promote outstanding chemical research, especially on creative and risky ideas.
Dr. Rint Sijbesma | EurekAlert!
Funding of Collaborative Research Center developing nanomaterials for cancer immunotherapy extended
28.06.2017 | Johannes Gutenberg-Universität Mainz
Zeolite catalysts pave the road to decentral chemical processes Confined space increases reactivity
28.06.2017 | Technische Universität München
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
28.06.2017 | Physics and Astronomy
28.06.2017 | Physics and Astronomy
28.06.2017 | Health and Medicine