Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Entangled frameworks limber up

20.09.2010
The degree of interconnectivity of molecular frameworks in microporous materials influences their structural flexibility and gas sorption

The quest to tune the three-dimensional (3D) molecular frameworks of materials called porous coordination polymers (PCPs) has taken a step forward thanks to a research team led by Ryotaro Matsuda and Susumu Kitagawa at the RIKEN SPring-8 Center in Harima and Kyoto University, Japan. The team, with members from Osaka Prefecture University, has described the influence of interpenetration of PCPs on the structural flexibility and gas sorption behavior of these materials1, which show great potential for use in gas storage, heterogeneous catalysis and as separation materials.

The interpenetrated molecular frameworks of PCPs are composed of metal ions and bridging organic ligands. Materials scientists initially thought that interpenetration would reduce the available capacity of the voids within the structure. However, other researchers showed recently that such entangled structures exhibit high gas-uptake, as a result of increased internal surface area. Interpenetration also increases the thermal stability of flexible frameworks.

These findings prompted Matsuda, Kitagawa and colleagues to make PCPs with the same chemical components but with either two-fold or three-fold interpenetration. Both forms of the 3D frameworks were made using a solvent templating method and were composed of zinc atoms and carboxylate- and pyridyl-based organic ligands. The two forms allowed the researchers to test the correlation between various physical properties and the degree of entanglement of the polymers.

Crystal structure analyses of the two forms indicated that non-covalent interactions, namely ð–ð interactions, in the three-fold structure are more significant than in the two-fold structure. Consequently, the two-fold structure has a more flexible structure and is of lower thermal stability than the more rigid three-fold PCP.

Using coincident x-ray powder diffraction and adsorption measurements, the team also showed that the two forms of structures have completely different carbon dioxide (CO2) adsorption behavior. The two-fold structure can adsorb four times the amount of saturated CO2 than the three-fold structure, owing to its greater flexibility and dynamic capability. Sorption occurs as a stepwise progression as a result of crystallographic transformations triggered by the addition and removal of guest molecules.

“The next challenge is the control of adsorption properties by external stimuli such as light or magnetic field to realize on-demand gas separation and storage,” says Matsuda. “This kind of material could be used to separate CO2 which is discharged from steelworks or to remove CO2 and hence keep air fresh in a spaceship.”

The corresponding author for this highlight is based at the Spatial Order Research Team, RIKEN SPring-8 Center

Journal information

1. Bureekaew, S., Sato, H., Matsuda, R., Kubota, Y., Hirose, R., Kim, J., Kato, K., Takata, M. & Kitagawa, S. Control of interpenetration for tuning structural flexibility influences sorption properties. Angewandte Chemie International Edition published online 2 July 2010 (doi: 10.1002/anie.201002259).

gro-pr | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6390
http://www.researchsea.com

More articles from Materials Sciences:

nachricht Scientist invents way to trigger artificial photosynthesis to clean air
26.04.2017 | University of Central Florida

nachricht Researchers invent process to make sustainable rubber, plastics
25.04.2017 | University of Delaware

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>