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Specifically, [the researchers] demonstrated two things in this study. First, they were able to integrate rGO [reduced graphene oxide] onto sapphire and silicon wafers – across the entire wafer.
Second, the researchers used high-powered laser pulses to disrupt chemical groups at regular intervals across the wafer. This disruption moved electrons from one group to another, effectively converting p-type rGO [positive rGO] to n-type rGO [negative rGO]. The entire process is done at room temperature and pressure using high-power nanosecond laser pulses, and is completed in less than one-fifth of a microsecond. The laser radiation annealing provides a high degree of spatial and depth control for creating the n-type regions needed to create p-n junction-based two-dimensional electronic devices.
The end result is a wafer with a layer of n-type rGO on the surface and a layer of p-type rGO underneath.
This is critical, because the p-n junction, where the two types meet, is what makes the material useful for transistor applications.
Graphene-oxide membranes have attracted considerable attention as promising candidates for new filtration technologies. Now the much sought-after development of making membranes capable of sieving common salts has been achieved.
Previous research at The University of Manchester found that if immersed in water, graphene-oxide membranes become slightly swollen and smaller salts flow through the membrane along with water, but larger ions or molecules are blocked.
The Manchester-based group have now further developed these graphene membranes and found a strategy to avoid the swelling of the membrane when exposed to water. The pore size in the membrane can be precisely controlled which can sieve common salts out of salty water and make it safe to drink.
Mr. Jijo Abraham and Dr. Vasu Siddeswara Kalangi were the joint-lead authors on the research paper: "The developed membranes are not only useful for desalination, but the atomic scale tunability of the pore size also opens new opportunity to fabricate membranes with on-demand filtration capable of filtering out ions according to their sizes." said Mr. Abraham.
This special material is a film of a special structure of carbon, a honeycomb lattice called graphene.
"Graphene is pure carbon that is made in a hot oven on top of a copper sheet in a vacuum," John Stetson, the chief technologist at Lockheed for this initiative explained to Business Insider. "Methane gas is put into the vacuum and the methane changes into a single film of carbon atoms all linked together tightly like chickenwire (at the atomic level) 1,000 times stronger than steel and tolerant of temperature, pressure and pH."
The sheet is dotted with holes that are one nanometer or less. These holes between carbon atoms trap the salt and other impurities.
Researchers in AMBER, the Science Foundation Ireland-funded materials science research centre hosted in Trinity College Dublin, have fabricated printed transistors consisting entirely of 2-dimensional nanomaterials for the first time. These 2D materials combine exciting electronic properties with the potential for low-cost production. This breakthrough could unlock the potential for applications such as food packaging that displays a digital countdown to warn you of spoiling, wine labels that alert you when your white wine is at its optimum temperature, or even a window pane that shows the day's forecast. The AMBER team's findings have been published today in the leading journal Science.
Led by Prof Coleman, in collaboration with the groups of Prof Georg Duesberg (AMBER) and Prof. Laurens Siebbeles (TU Delft, Netherlands), the team used standard printing techniques to combine graphene nanosheets as the electrodes with two other nanomaterials, tungsten diselenide and boron nitride [aka, 'white graphene'] as the channel and separator (two important parts of a transistor) to form an all-printed, all-nanosheet, working transistor.
Now, a variation of Vantablack (known as Vantablack S-VIS) is available in a spray-on form that blocks 99.8 percent of ultraviolet, visible and infrared light — enough to make an otherwise detailed 3D object appear as a flat black void.
"If you see [Vantablack S-VIS] on a flat surface on its own, with no other black material to reference it against, it just looks like a black velvet surface," Ben Jensen, chief technical officer for Surrey NanoSystems, recently told the Australian Broadcasting Corp. (ABC). "If you see it on a 3D object, like crinkled foil, the coated side still looks like a black two-dimensional flat surface. It's only when you turn it around and you realize that it's got a lot of dimensionality, that you grasp how different it is."
Using five ingredients -- silicon, boron, carbon, nitrogen and hydrogen -- [researchers have] created a liquid polymer that can transform into a ceramic with valuable thermal, optical and electronic properties. The waterlike polymer, which becomes a ceramic when heated, also can be mass-produced.
When combined with carbon nanotubes, the polymer has even more applications. It can create a black material that can absorb all light -- even ultraviolet and infrared light -- without being damaged. The combined nanomaterial can withstand extreme heat of 15,000 watts per square centimeter, which is about 10 times more heat than a rocket nozzle.
• The presence of silicon and graphenelike carbon in the ceramic can improve electrodes for lithium-ion batteries.
The ceramic derived from this polymer has a random structure that is generally not observed in traditional ceramics. The silicon in the ceramic bonds to nitrogen and carbon but not boron; boron bonds to nitrogen but not carbon; and carbon bonds to another carbon to form graphenelike strings. This unique structure provides stability at high temperature by delaying reaction with oxygen.
The engineers worked out carefully controlled procedures to place single sheets of graphene onto an expensive wafer. They then grew semiconducting material over the graphene layer. They found that graphene is thin enough to appear electrically invisible, allowing the top layer to see through the graphene to the underlying crystalline wafer, imprinting its patterns without being influenced by the graphene.
Graphene is also rather "slippery" and does not tend to stick to other materials easily, enabling the engineers to simply peel the top semiconducting layer from the wafer after its structures have been imprinted.
"The industry has been stuck on silicon, and even though we've known about better performing semiconductors, we haven't been able to use them, because of their cost," Kim says. "This gives the industry freedom in choosing semiconductor materials by performance and not cost."
Saint Jean Carbon Inc. …, a carbon science company engaged in the design and build of green energy storage, green energy creation and green re-creation through the use of carbon materials. The Company is pleased to announce the results of the graphene battery project phase one of three, previously announced on January 19th, 2017. …Both batteries were made with the same material, battery "A" graphite anode and "B" graphene anode.
The performance results are as follows; the theoretical capacity of the graphite anode: 372 mAh/g the theoretical capacity of the graphene anode: 700 mAh/g. Over 100 cycles the discharge capacity for the graphite was 200 to 220 mAh/g and for the graphene 310 to 330 mAh/g. The testing procedures: charge to 3V at 500 mA/g and discharge to 0.05V at 100 mA/g. Neither the graphite nor graphene were optimized so the variations in the results need to be further tested.
Paul Ogilvie, CEO, commented: "The project started as material comparison, the same material but applied in to different states, graphene and graphite. It will be really interesting to see if we can scale up to a size of battery that would be meaningful.
Qian Cheng, a researcher from NEC Corporation in Japan, has developed a porous graphene sponge additive, known as Magic G, that can be used in both the anode and the cathode of a lithium-ion battery to increase its rate and power performance.
When compared to other non-Magic G Li-ion batteries, the addition of 0.5 %wt addition into the anode improved the charge capacity retention from 56% to 77% at 6 cycles and from 7% to 45% at 10 cycles.
In the cathode, the same amount of Magic G was incorporated and showed an increase in the discharge capacity rate from 43% to 76% at 6 cycles and an increase from 16% to 40% at 10 cycles.
Now, Nippon Shokubai Co.,... has resolved various problems associated with the oxidation reaction, making it possible to scale up production “several dozens of times” more than laboratory scale. The achievement, performed in collaboration with Okayama University and support from the New Energy and Industrial Technology Development Organization,.. enabled the company to prepare materials in quantities sufficient for application development.
An international team of scientists has developed a new way to produce single-layer graphene from a simple precursor: ethene - also known as ethylene - the smallest alkene molecule, which contains just two atoms of carbon.
By heating the ethene in stages to a temperature of slightly more than 700 degrees Celsius—hotter than had been attempted before - the researchers produced pure layers of graphene on a rhodium catalyst substrate. The stepwise heating and higher temperature overcame challenges seen in earlier efforts to produce graphene directly from hydrocarbon precursors.
It will be distributed in the UK through The Graphene Company, which claims Graphenstone [paint manufacturer] is the most environmentally friendly paint in the world.
Another environmental benefit comes from graphene's thinness and strength, which means less paint is required to achieve a durable finish that is resistant to corrosion. The Graphene Company says a litre of paint would cover two eight-metre-square coats.
Manufacturer Graphenstone originates from Seville, Spain, where the purest qualities of lime in the world can be found.
But while this super-pure lime makes for highly absorbent and breathable paint, it lacks in strength. This is where graphene comes in.
"For the first time in history you've got this fusion of one of the oldest and most trusted building materials, lime, with the very latest nanotechnology," said Folkes.
Researchers at the Okinawa Institute of Science and Technology (OIST) have reported that using graphene film managed to drastically enhance the quality of electron microscopy images.
Using low energy electrons does, however, have a significant drawback: because of its high sensitivity with matter, a low energy electron beam would interact with the target sample but also with everything else (like the support plate and film on which the sample is laying). The resulting image would not distinguish the study material from the background. To counter this effect, graphene was used; The researchers synthesized a film made of a single layer of graphene on which the biological samples, like the viruses they study, will be displayed. Graphene's highly conductive nature made sure that the low energy electrons will interact very little with the background graphene layer and much more with the virus sample which will stand out with a great contrast. This high conductivity also prevents "charging-up," an accumulation of electrons on the film that would distort the final image. The thinness of the film also provides a much brighter background, resulting in a much better contrast with the study material, than conventional carbon films.
Professor Baohua Jia and Dr Han Lin lead a team developing the Bolt Electricity Storage Technology (BEST) battery – a graphene oxide-based supercapacitor offering high performance and low-cost energy storage.
The seeds of the BEST project were sown in 2015, with a $375,000 Australian Research Council Discovery Project grant for direct laser printing of thin ﬁlms of activated graphene oxide. Graphene material is very porous, which gives it a hugely increased surface area on which to store electrical charge. The project aims to create a supercapacitor that could more efficiently collect, store and discharge the energy collected by solar cells.
"In this process, no ions are being generated or being killed," Dr Lin says. "They are maintained by charge and discharge, and are just moved around. Moving ions doesn't degrade the supercapacitor, so it can charge millions of times, in theory. Usually, a supercapacitor can work for at least 10,000 life-cycles."
That "in theory" is important. The efficacy of graphene oxide has been proven in the laboratory.
Making a commercial prototype is the next step.
The Thought Emporium’s approach to harvesting graphene from graphite is a two-step process starting with electrochemical exfoliation. Strips of thin graphite foil are electrolyzed in a bath of ferrous sulfate, resulting in the graphite delaminating and flaking off into the electrolyte. After filtering and cleaning, the almost graphene is further exfoliated in an ultrasonic cleaner. The result is gram quantity yields with very little work and at low cost.
This technique requires two things: a commercially available suspension of low-quality graphene flakes, and kinetic energy. The fluid is passed through a de Laval nozzle, which is generally used to accelerate the expulsion of gas in a jet engine. As a fluid (liquid or gas) moves through the nozzle, its pinched center forces the flow intensity to increase, like putting your thumb over half of a hose. With a de Laval nozzle, the researchers can smash graphene flakes into just about any hard surface with enough force to flatten them out, Silly Putty style.
Ora Sound, a Montreal-based startup, hopes to change all that. On 20 June, it unveiled a Kickstarter campaign for a new audiophile-grade headphone that uses cones, also known as membranes, made of a form of graphene. “To the best of our knowledge, we are the first company to find a significant, commercially viable application for graphene,” says Ora cofounder Ari Pinkas, noting that the cones in the headphones are 95 percent graphene.
The Ora prototype is clearly superior to the comparison models, but that’s not much of a surprise. The other units sell for about $100, while the Ora headphones will have a suggested retail of $499 when they are in production.
Gaskell claims that Ora’s graphene cone weighs only one-third as much as a comparable mylar one, which translates into an increase in battery life of up to 70 percent.