A team of researchers in Japan has developed a porous material, decorated with a highly reactive ‘species’ of molecules that can be activated remotely using a technique called photoactiviation. Since porous materials have large surface areas for a given volume, they can be used for gas storage, and for the acceleration of chemical reactions. The ability to turn these molecular species ‘on’ or ‘off’ increases their utility. The novel porous material is also unique for its high degree of reactivity, which traditionally has been difficult to achieve while maintaining material stability.
Ryotaro Matsuda , Susumu Kitagawa of Kyoto University, the Japan Science and Technology Agency and the RIKEN SPring-8 Center and their colleagues, from these institutes and Japan Synchrotron Radiation Research Institute, made their porous material from a polymer network with an interlinked structure constructed from aryl azide molecules, which are relatively inactive but produce the highly reactive molecule aryl nitrene when irradiated with ultraviolet light.
The researchers exposed a single crystal or crystalline powder of their novel polymer to ultraviolet light and then measured the result with infrared spectroscopy, spin resonance and x-ray diffraction. Their results indicated that the irradiation converted a significant fraction of the dormant azides into reactive nitrenes, without disrupting the underlying porous network. The product was therefore a set of dense, highly reactive nanoscale pores.
The reactivity of these pores imparted new functionality to the polymer network, explains Matsuda. For example, the polymer’s oxygen storage capacity increased by a factor of 29 after irradiation. The researchers also observed nitrenes reacting with carbon monoxide, suggesting that the polymer could be used to detect or filter this dangerous gas. Furthermore, because reactive species besides nitrenes can also be activated in this way, the technique has the potential to allow the capture and conversion of a variety of gases. The ability to increase the storage capacity or the speed of a chemical reaction remotely, and at a particular time, also significantly increases the range of available applications, he notes.
The approach represents the confluence of well-understood photochemistry and the materials science behind porous networks, with potential implications for devices such as sensors and purifiers. However, while the initial results are promising, several critical features need to developed, according to Matsuda. “In addition to demonstrating the trapping of gases besides oxygen and carbon monoxide, we need to make our material reusable,” he says. “Currently, it cannot desorb gas molecules after the photoreaction, and therefore cannot be reused.”
The corresponding author for this highlight is based at the Spatial Order Research Team, RIKEN SPring-8 Center
1. Sato, H., Matsuda, R., Sugimoto, K., Takata, M. & Kitagawa, S. Photoactivation of a nanoporous crystal for on-demand guest trapping and conversion. Nature Materials 9, 661–666 (2010)
gro-pr | Research asia research news
Watching atoms move in hybrid perovskite crystals reveals clues to improving solar cells
22.11.2017 | University of California - San Diego
Fine felted nanotubes: CAU research team develops new composite material made of carbon nanotubes
22.11.2017 | Christian-Albrechts-Universität zu Kiel
High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons
The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
24.11.2017 | Physics and Astronomy
24.11.2017 | Health and Medicine
24.11.2017 | Earth Sciences