Category Chemistry/Nanotechnology

Stefan Freunberger, beneficiary of an ERC grant at TU Graz, investigates ageing processes in non-aqueous batteries. Credit: © Lunghammer – TU Graz

It has been known in biology for a long time that the excited oxygen molecule singlet oxygen is the main cause of aging in cells. To counter this, nature uses an enzyme called superoxide dismutase to eliminate superoxide as a free radical. Superoxide also occurs in cell respiration for energy production and is the preliminary stage and thus source of singlet oxygen. TU Graz’s Stefan Freunberger has now stumbled upon astonishing parallels of oxygen chemistry in battery systems.

He investigates aging processes in non-aqueous batteries, such as oxygen batteries, ie, battery systems in which oxygen reacts with lithium, sodium magnesium, for example...

This computer-generated model shows the spherical core of the quantum dot nanoparticle (in red) along with the ‘flying saucer’ shape of the outer shell (in yellow). The tension in the core induced by the shell affects the electronic states and lowers the energy threshold required to trigger the laser. Credit: Alex Voznyy

Research team ‘squashes’ the shape of nanoparticles, enabling inexpensive lasers that continuously emit light in a customized rainbow of colors. Fresh insights into living cells, brighter video projectors and more accurate medical tests are just 3 of the innovations that could result from a new way of fabricating lasers...

This tiny US flag — just a few nanometers wide and invisible to the naked eye — is arguably the world’s smallest image of Old Glory, according to its creators at the University of Texas at Dallas. In an experiment, the nanoflag pattern emerged unexpectedly as sheets of the “stripe” material — molybdenum ditelluride — were heated to about 450 degrees Celsius, at which point its atoms began to rearrange and form new structures — the ‘stars’ in this false-color image. Each star consists of six central atoms of molybdenum surrounded by six atoms of tellurium. Stacked on top of one another, the stars form nanowires that might power advanced electronics. The transformation from stripes to stars is reported in the journal Advanced Materials. Credit: University of Texas at Dalla

For several years,...

This is a sample of transparent polycrystalline cubic silicon nitride with a diameter of approximately two millimeters, synthesized at DESY. Credit: Norimasa Nishiyama, DESY/Tokyo Tech

Scientists synthesize 1st sample of transparent silicon nitride, ie popular industrial ceramic DESY.The result is a super-hard window made of cubic silicon nitride that can potentially be used under extreme conditions like in engines. Cubic silicon nitride (c-Si3N4) forms under high pressure and is the 2nd hardest transparent nanoceramic after diamond but can withstand substantially higher temperatures.

“Silicon nitride is a very popular ceramic in industry,” explains lead author Dr. Norimasa Nishiyama from DESY, now is an associate professor at Tokyo Institute of Technology...