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 Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>