How To Recycle Carbon Dioxide

An international team of scientists led by Liang-shi Li at Indiana University (IU) has achieved a new milestone in the quest to recycle carbon dioxide in the Earth’s atmosphere into carbon-neutral fuels and others materials.

 

The chemists have engineered a molecule that uses light or electricity to convert the greenhouse gas carbon dioxide into carbon monoxide — a carbon-neutral fuel source — more efficiently than any other method of “carbon reduction.”

molecular leaf

If you can create an efficient enough molecule for this reaction, it will produce energy that is free and storable in the form of fuels,” said Li, associate professor in the IU Bloomington College of Arts and Sciences‘ Department of Chemistry. “This study is a major leap in that direction.”

Burning fuel — such as carbon monoxide — produces carbon dioxide and releases energy. Turning carbon dioxide back into fuel requires at least the same amount of energy. A major goal among scientists has been decreasing the excess energy needed.

This is exactly what Li’s molecule achieves: requiring the least amount of energy reported thus far to drive the formation of carbon monoxide. The molecule — a nanographene-rhenium complex connected via an organic compound known as bipyridine — triggers a highly efficient reaction that converts carbon dioxide to carbon monoxide. The ability to efficiently and exclusively create carbon monoxide is significant due to the molecule’s versatility.

Carbon monoxide is an important raw material in a lot of industrial processes,” Li said. “It’s also a way to store energy as a carbon-neutral fuel since you’re not putting any more carbon back into the atmosphere than you already removed. You’re simply re-releasing the solar power you used to make it.

The secret to the molecule’s efficiency is nanographene — a nanometer-scale piece of graphite, a common form of carbon (i.e. the black “lead” in pencils) — because the material’s dark color absorbs a large amount of sunlight.

Li said that bipyridine-metal complexes have long been studied to reduce carbon dioxide to carbon monoxide with sunlight. But these molecules can use only a tiny sliver of the light in sunlight, primarily in the ultraviolet range, which is invisible to the naked eye. In contrast, the molecule developed at IU takes advantage of the light-absorbing power of nanographene to create a reaction that uses sunlight in the wavelength up to 600 nanometers — a large portion of the visible light spectrum.

Essentially, Li said, the molecule acts as a two-part system: a nanographeneenergy collector” that absorbs energy from sunlight and an atomic rheniumengine” that produces carbon monoxide. The energy collector drives a flow of electrons to the rhenium atom, which repeatedly binds and converts the normally stable carbon dioxide to carbon monoxide.

The idea to link nanographene to the metal arose from Li’s earlier efforts to create a more efficient solar cell with the carbon-based material. “We asked ourselves: Could we cut out the middle man — solar cells — and use the light-absorbing quality of nanographene alone to drive the reaction?” he said.

Next, Li plans to make the molecule more powerful, including making it last longer and survive in a non-liquid form, since solid catalysts are easier to use in the real world.

The process is reported in the Journal of the American Chemical Society.

Source: http://news.indiana.edu/

New Material Ten Times Stronger Than Steel, Designed From Graphene

A team of researchers at MIT has designed one of the strongest lightweight materials known, by compressing and fusing flakes of graphene, a two-dimensional form of carbon. The new material, a sponge-like configuration with a density of just 5 percent, can have a strength 10 times that of steel. In its two-dimensional form, graphene is thought to be the strongest of all known materials. But researchers until now have had a hard time translating that two-dimensional strength into useful three-dimensional materials.

The new findings show that the crucial aspect of the new 3-D forms has more to do with their unusual geometrical configuration than with the material itself, which suggests that similar strong, lightweight materials could be made from a variety of materials by creating similar geometric features.

graphene material

The team was able to compress small flakes of graphene using a combination of heat and pressure. This process produced a strong, stable structure whose form resembles that of some corals and microscopic creatures called diatoms. These shapes, which have an enormous surface area in proportion to their volume, proved to be remarkably strong. “Once we created these 3-D structures, we wanted to see what’s the limit — what’s the strongest possible material we can produce,” says Zhao Qin, research scientist at MIT. To do that, they created a variety of 3-D models and then subjected them to various tests. In computational simulations, which mimic the loading conditions in the tensile and compression tests performed in a tensile loading machine, “one of our samples has 5 percent the density of steel, but 10 times the strength,” Qin says.
The findings have been reported in the journal Science Advances.

Source: http://news.mit.edu/

Impenetrable Body-Armor To Protect Soldiers

A team of engineers from the University of California San Diego (UC San Diego) has developed and tested a type of steel with a record-breaking ability to withstand an impact without deforming permanently. The new steel alloy could be used in a wide range of applications, from drill bits, to body armor for soldiers, to meteor-resistant casings for satellites. The material is an amorphous steel alloy, a promising subclass of steel alloys made of arrangements of atoms that deviate from steel’s classical crystal-like structure, where iron atoms occupy specific locations.

Researchers are increasingly looking to amorphous steel as a source of new materials that are affordable to manufacture, incredibly hard, but at the same time, not brittle. The researchers believe their work on the steel alloy, named SAM2X5-630, is the first to investigate how amorphous steels respond to shock. SAM2X5-630 has the highest recorded elastic limit for any steel alloy, according to the researchers—essentially the highest threshold at which the material can withstand an impact without deforming permanently. The alloy can withstand pressure and stress of up to 12.5 giga-Pascals or about 125,000 atmospheres without undergoing permanent deformations.

record breaking steelTransmission electron microscopy image showing different levels of crystallinity embedded in the amorphous matrix of the alloy. Watch a video of the alloy being tested, click the image.
Because these materials are designed to withstand extreme conditions, you can process them under extreme conditions successfully,” said Olivia Graeve, a professor of mechanical engineering at the Jacobs School of Engineering at UC San Diego, who led the design and fabrication effort. Veronica Eliasson, an assistant professor at USC, led the testing efforts.

The researchers, from the University of California, San Diego, the University of Southern California and the California Institute of Technology, describe the material’s fabrication and testing in a recent issue of Nature Scientific Reports.

Source: http://jacobsschool.ucsd.edu/

Transparent Wood Brightens Homes

When it comes to indoor lighting, nothing beats the sun’s rays streaming in through windows. Soon, that natural light could be shining through walls, too. Scientists from the KTH Royal Institute of Technology (Sweden) have developed transparent wood that could be used in building materials and could help home and building owners save money on their artificial lighting costs. Their material, reported in ACS’ journal Biomacromolecules, also could find application in solar cell windows.

transparent wood

Homeowners often search for ways to brighten up their living space. They opt for light-colored paints, mirrors and lots of lamps and ceiling lights. But if the walls themselves were transparent, this would reduce the need for artificial lighting — and the associated energy costs. Recent work on making transparent paper from wood has led to the potential for making similar but stronger materials. Lars Berglund and colleagues from KTH the wanted to pursue this possibility.

The researchers removed lignin from samples of commercial balsa wood. Lignin is a structural polymer in plants that blocks 80 to 95 percent of light from passing through. But the resulting material was still not transparent due to light scattering within it. To allow light to pass through the wood more directly, the researchers incorporated acrylic, often known as Plexiglass. The researchers could see through the resulting material, which was twice as strong as Plexiglass. Although the wood isn’t as crystal clear as glass, its haziness provides a possible advantage for solar cells. Specifically, because the material still traps some light, it could be used to boost the efficiency of these cells, the scientists note.

Source: http://www.acs.org/
AND
https://www.kth.se/

How To Store Electricity In Paper

Researchers at Linköping University’s Laboratory of Organic Electronics, Sweden, have developed power paper – a new material with an outstanding ability to store energy. The material consists of nanocellulose and a conductive polymer.

One sheet, 15 centimetres in diameter and a few tenths of a millimetre thick can store as much as 1 F, which is similar to the supercapacitors currently on the market. The material can be recharged hundreds of times and each charge only takes a few seconds.

It’s a dream product in a world where the increased use of renewable energy requires new methods for energy storage – from summer to winter, from a windy day to a calm one, from a sunny day to one with heavy cloud cover.

Power-paper

Thin films that function as capacitors have existed for some time. What we have done is to produce the material in three dimensions. We can produce thick sheets,” says Xavier Crispin, professor of organic electronics and co-author to the article just published in Advanced Science.

The material, power paper, looks and feels like a slightly plasticky paper and the researchers have amused themselves by using one piece to make an origami swan – which gives an indication of its strength.

The structural foundation of the material is nanocellulose, which is cellulose fibres which, using high-pressure water, are broken down into fibres as thin as 20 nm in diameter. With the cellulose fibres in a solution of water, an electrically charged polymer (PEDOT:PSS), also in a water solution, is added. The polymer then forms a thin coating around the fibres.

The covered fibres are in tangles, where the liquid in the spaces between them functions as an electrolyte,” explains Jesper Edberg, doctoral student, who conducted the experiments together with Abdellah Malti, who recently completed his doctorate. Other co-authors are researchers from KTH Royal Institute of Technology, Innventia, Technical University of Denmark and the University of Kentucky.

The results have been published in Advanced Science.

Source: http://www.liu.se/

“Chewing gum” Material 3 Times Stronger Than Steel

Creating futuristic, next generation materials called ‘metallic glass’ that are ultra-strong and ultra-flexible will become easier and cheaper, based on UNSW Australia research that can predict for the first time which combinations of metals will best form these useful materials.

Just like something from science fiction – think of the Liquid-Metal robot assassin in the Terminator films – these materials behave more like glass or plastic than metal.

While still being metals, they become as malleable as chewing gum when heated and can be easily moulded or blown like glass. They are also three times stronger and harder than ordinary metals, on average, and are among the toughest materials known.

 

liquid_terminatorThe Terminator‘s Liquid Metal Man: While still being metals, they become as malleable as chewing gum when heated and can be easily moulded or blown like glass.

They have been described as the most significant development in materials science since the discovery of plastics more than 50 years ago,” says study author, UNSW’s Dr Kevin Laws.

Most metals are crystalline when solid, with their atoms arranged in a highly organised and regular manner. Metallic glass alloys, however, have a highly disordered structure, with the atoms arranged in a non-regular way.

Source: https://newsroom.unsw.edu.au/

Invisible QR Codes

An invisible quick response (QR) code has been created by researchers in an attempt to increase security on printed documents and reduce the possibility of counterfeiting, a problem which costs governments and private industries billions of dollars each year. A team from the University of South Dakota and South Dakota School of Mines and Technology believe the new style of QR code could also be used to authenticate virtually any solid object.
The QR code is made of tiny nanoparticles that have been combined with blue and green fluorescence ink, which is invisible until illuminated with laser light. It is generated using computer-aided design (CAD) and printed onto a surface using an aerosol jet printer. The development process can be viewed in this video.

Enjoy the video: http://www.youtube.com/watch?v=5eqtQq1Ol14

Source: http://www.iop.org/news/12/sep/page_57101.html

“Invisible” Sounds

Many of the current experimental "invisibility cloaks" are based around the same idea – light coming from behind an object is curved around it and then continues on forward to a viewer. That person is in turn only able to see what's behind the object, and not the object itself. Scientists from Germany's Karlsruhe Institute of Technology (KIT) have applied that same principle to sound waves, and created what could perhaps be described as a "silence cloak." For the experiments, Dr. Nicolas Stenger, from KIT,  constructed a relatively small, millimeter-thin plate, made of both soft and hard microstructured polymers. Different rings of material within the plate resonated at different frequencies, over a range of 100 Hertz.


 

 

When viewed from above, it was observed that sound wave vibrations were guided around a central circular area in the plate, unable to either enter or leave that region. "Contrary to other known noise protection measures, the sound waves are neither absorbed nor reflected," said Stenger's colleague, Prof. Martin Wegener. "It is as if nothing was there."

Source; http://prl.aps.org/abstract/PRL/v107/i17/e173901

New Holographic Machine in 2012

A Leuven, Belgium-based R&D lab for nanoelectronics has come up with a process that might bring holographic to everyday life. Scientists at Imec believe, as do other researchers, that holographic images are the answer toward resolving the eye strain and headaches that go along with present-day 3-D viewing. Their work involves creating moving pixels. They are constructing holographic displays by shining lasers on microelectromechanical systems (MEMS) platforms that can move up and down like small, reflective pistons. “Holographic visualization promises to offer a natural 3-D experience for multiple viewers, without the undesirable side-effects of current 3D stereoscopic visualization (uncomfortable glasses, strained eyes, fatiguing experience),” the company states.

 

Click on the image to see the video

In their nanoscale system, they work with chips made by growing a layer of silicon oxide on to silicon wafer. They etch square patches of the silicon oxide. The result is a checkerboard-like pattern where etched-away pixels are nanometers lower than their neighbors. A reflective aluminum coating tops the chip. When laser light shines on the chip, it bounces off of the boundary between adjacent pixels at an angle. Diffracted light interferes constructively and destructively to create a 3-D picture where small mirrored platforms are moving up and down, many times a second, to create a moving projection. The process can also be described as the pixels closer to the light interfering with it one way and those further off, in another. The small distances between them generate the image that the eye sees. Imec hopes to construct the first, proof-of-concept moving structures by mid-2012.” .
Source: http://www2.imec.be/be_en/research/imaging-systems/holographic-displays.html

A new competitor to graphene

In early 2011, the The Laboratory of Nanoscale Electronics and Structuresab (Ecole Polytechnique Fédérale de Lausanne) in Switzerland, unveiled the potential of molybdenum disulfide (MoS2), a relatively abundant, naturally occurring mineral. Its structure and semi-conducting properties make it an ideal material for use in transistors. It can thus compete directly with silicon, the most highly used component in electronics, and on several points it also rivals graphene.

"The main advantage of MoS2 is that it allows us to reduce the size of transistors, and thus to further miniaturize them," explains Andreas Kis, LANES director, who recently published two articles on the subject in the scientific journal ACS Nano. It has not been possible up to this point to make layers of silicon less than two nanometers thick, because of the risk of initiating a chemical reaction that would oxidize the surface and compromise its electronic properties. Molybdenite, on the other hand, can be worked in layers only three atoms thick, making it possible to build chips that are at least three times smaller. At this scale, the material is still very stable and conduction is easy to control.

 

Source; http://pubs.acs.org/action/doSearch?action=search&searchText=molybdenum+disulfide+&qsSearchArea
=searchText&type=within&publication=40025957

Transparent material ‘Best Invention of 2011’

Drs Ali Aliev, Yuri Gartstein and Ray Baughman, of the University of Texas at Dallas (UTD), have succeeded in producing what is technically referred to as the "mirage effect from thermally modulated transparent carbon nanotube sheets," or, as some in the popular press have termed it: an 'invisibility cloak'." The key to this breakthrough are carbon nanotubes—the successful result of another ongoing AFOSR-funded UTD program—that have the ability to disappear when rapidly heated. In reality, this effect is due to photothermal deflection, or a mirage effect, quite similar to what a driver may experience when a highway in the distance becomes so hot that a section of the road may look like a pool of water. This is due to the bending of the light around the hot road surface wherein the driver actually sees the reflected sky in place of the pavement. The carbon nanotubes create much the same effect when heated.

The Air Force Office of Scientific Research – ASFOR –, located in Arlington, Virginia, continues to expand the horizon of scientific knowledge through its leadership and management of the Air Force's basic research program. As a vital component of the Air Force Research Laboratory, AFOSR's mission is to discover, shape and champion basic science that profoundly impacts the future Air Force.
Transparent material breakthrough: One of Time magazine's 'Best Inventions of 2011'
Source: http://nanotech.utdallas.edu/personnel/staff/aliev.html