Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Pores for thought

28.09.2009
Porous coordination polymers that strongly adsorb polar guest molecules can be made using a ligand with separated positive and negative charges

A porous coordination polymer (PCP) that strongly adsorbs methanol, a model guest molecule, has been prepared by Masakazu Higuchi from the RIKEN SPring-8 Center in Harima and co-workers from the University of Kyoto, the Japan Synchrotron Radiation Research Institute and Osaka Prefecture University1.

The new material is important because porous materials that can adsorb guest molecules offer opportunities in finding ways to store hydrogen fuel, and to sequester waste gas such as carbon dioxide, which can reduce the impact of burning fossil fuels. Porous coordination polymers (PCPs) provide a particularly attractive option in both endeavors because they contain micropores and their surfaces can be designed to have specific properties.

Also known as metal–organic frameworks (MOFs), PCPs are formed between metal ions—often from transition metals such as zinc—and well-defined organic ligands that can bond to more than one metal atom. With sufficiently rigid ligands, such that a single ligand cannot just coordinate to a single metal ion, it is possible to produce a continuous network of metal ions held together by the ligands. It is within the pores of these PCPs that guest molecules such as gases can be accommodated.

For guest molecules to be adsorbed efficiently they must interact with the pore walls. “We thought that electrostatically charged walls would be beneficial, but this introduced a new problem,” explains Higuchi, “the overall structure must be electrically neutral and the counter-ions required to achieve this occupy the pores of the PCP meaning that they are blocked to guest molecules.”

Higuchi and colleagues’ PCP is based on the coordination of zinc ions with a zwitterionic ligand, which is electrically neutral, but carries separated positive and negative charges. They showed that guest molecules of methanol adsorb more strongly than a similar PCP made with uncharged ligands. It can also adsorb more guest molecules because the pores are not blocked by counter-ions.

The zwitterionic ligand used in the new material described by Higuchi and his colleagues means that the pore walls are highly charged but additional counter-ions are not required. They have also shown that the material adsorbs methanol more strongly than a similar PCP with uncharged pore walls. “In the future, we plan to investigate how other guest molecules interact with the charged pore surface” says Higuchi. “Ultimately, we hope to see this develop into a material that can be made on an industrial scale.”

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

1. Higuchi, M., Tanaka, D., Horike, S., Sakamoto, H., Nakamura, K.,Takashima, Y., Hijikata, Y., Yanai, N., Kim, J., Kato, K. et al. Porous coordination polymer with pyridinium cationic surface, [Zn2(tpa)2(cpb)]. Journal of the American Chemical Society 131, 10336–10337 (2009).

Saeko Okada | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6052
http://www.researchsea.com

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>