The material is made of graphene nanoribbons atom-thick strips of carbon created by splitting nanotubes a process also invented by the Tour lab
#Aligned carbon nanotube/graphene sandwiches By in situ nitrogen doping and structural hybridization of carbon nanotubes (CNTS) and graphene via a two-step chemical vapor deposition (CVD) scientists have fabricated nitrogen-doped aligned carbon nanotube/graphene (N-ACNT/G) sandwiches
with three-dimensional (3d) electron transfer pathways interconnected ion diffusion channels and enhanced interfacial affinity and activity.
CNTS and graphene the most highlighted sp2-bonded carbon nanomaterials over the past decades have attracted enormous attention in the area of energy storage heterogeneous catalysis healthcare environmental protection as well as nanocomposites
However the heteroatom-containing nanocarbon tends to aggregate due to strong Van der waals interactions and large surface area explosion thereby constantly limiting the demonstration of their intrinsic physical properties and performances in as-fabricated materials and practical devices.
The combination of CNTS and graphene into 3d hybrid composites can usually mitigate the self-aggregation
and restacking of nanocarbon materials and also amplify physical properties at macroscale. Up to now several strategies have been explored to fabricate such CNTS/graphene hybrids including post-organization methods
and in situ growth while integration of high-quality CNTS and graphene without barrier layers is still difficult.
A team from Tsinghua University (China) led by Prof. Qiang Zhang and Fei Wei have fabricated now successfully sandwich-like N-ACNT/G hybrids via a two-step catalytic growth on bifunctional natural materials.
Aligned CNTS were intercalated firstly into the interlayer spaces of the layered catalyst embedded with metal nanoparticles (NPS) through a low-temperature (L-T) CVD
and graphene was deposited sequentially onto the surface of lamellar flakes at the bottom of aligned CNTS through a high-temperature (H-T) CVD.
After catalyst removal alternative aligned CNTS and graphene were connected vertically to each other in long-range periodicity thereby forming a sandwich-like structure.
The key issue for the fabrication of the novel N-ACNT/G architecture is that the high-quality aligned CNTS
Org''Thereby the seamless connection of high-quality aligned CNTS and graphene provided 3d electron transfer pathways and interconnected ion diffusion channels.
which was about 65%higher than that of sole aligned CNTS. Even at a high current density of 5. 0 C a reversible capacity of ca. 770 mah g-1 can be achieved.
Zhang elaborated The seamless junction of CVD-grown aligned CNTS and graphene provides rapid electron transfer and mechanical robustness.
Rational hybridization of N-doped graphene/carbon nanotubes for oxygen reduction and oxygen evolution reaction More information:
Tang C Zhang Q Zhao MQ Huang JQ Cheng XB Tian GL Peng HJ Wei F. Nitrogen-Doped Aligned Carbon nanotube
In a paper first published online on Sept. 9 in the journal Nature Chemistry, Mallouk and colleagues at Penn State and the Research center for Exotic Nanocarbons at Shinshu University, Japan, describe a method called intercalation,
While one-dimensional materials such as carbon nanotubes and nanowires also allow excellent electrostatics and at the same time possess band gap they are not suitable for low-cost mass production due to their process complexities she said.
Presenting their findings today 5 august 2014 in the journal Nanotechnology the researchers have demonstrated the material's superior performance compared to commercially available carbon graphene and carbon nanotubes.
and carbon nanotubes as reported in previous studies. Explore further: Nano-supercapacitors for electric cars More information:
This coating is mad e of carbon nanotubes-each 10000 times thinner than a human hair wrote Ian Johnston in The Independent on Sunday.
The manufacture of`super-black`carbon nanotube-based materials has required traditionally high temperatures preventing their direct application to sensitive electronics or materials with relatively low melting points.
and nanotubes using any method they like and use the shrinking action to compact them into a higher density."
During the procedure, the carbon nanotubes and thus the pore size shrink to a lesser extent than they would in the absence of the confining template
#Chirality-controlled growth of single-walled carbon nanotubes Recently, Professor Li Yan's research team developed a novel strategy to produce single-walled carbon nanotubes with specific chirality by applying a new family of catalysts,
"We need to use structure specific carbon nanotubes for real applications. The structure controlled growth has been a dream of our field for about 20 years.
I believe her idea to use W-based catalyst is the landmark of growth of carbon nanotubes.
We expect a plenty of very useful applications of carbon nanotubes based on her new discovery, "said Professor Shigeo Maruyama from The University of Tokyo,
who also serves the president of Fullerene, Carbon nanotubes, and Graphene research Society of Japan. Single-walled carbon nanotube (SWNT
which can be considered as a seamlesscylinder formed by rolling a piece of graphene, may be either metallic
In 2009, the International Technology Roadmap for Semiconductors (ITRS) selected carbon-based nanoelectronics to include carbon nanotubes
"the main hurdle (of carbon-based electronics) is our current inability to produce large amounts of identical nanostructureshere is no reliable way to directly produce a single CNT type such as will be needed in a large integrated system."
Experimental evidence and theoretical simulation reveal that the good structural match between the carbon atom arrangement around the nanotube circumference
"The chirality-specific growth of single-walled carbon nanotubes is the most challenging and important issue in the field,
This development is very important for the applications of carbon nanotubes in many fields especially nanoelectronics. c
#Lab unzips nanotubes into ribbons by shooting them at a target (Phys. org) Carbon nanotubes unzipped into graphene nanoribbons by a chemical process invented at Rice university are finding use in all kinds of projects
The Rice lab of materials scientist Pulickel Ajayan discovered that nanotubes that hit a target end first turn into mostly ragged clumps of atoms.
But nanotubes that happen to broadside the target unzip into handy ribbons that can be used in composite materials for strength
Until now we knew we could use mechanical forces to shorten and cut carbon nanotubes. This is the first time we have showed carbon nanotubes can be unzipped using mechanical forces.
The researchers fired pellets of randomly oriented multiwalled carbon nanotubes from a light gas gun built by the Rice lab of materials scientist Enrique Barrera with funding from NASA.
The pellets impacted an aluminum target in a vacuum chamber at about 15000 miles per hour. When they inspected the resulting carbon rubble they found nanotubes that smashed into the target end first
or at a sharp angle simply deformed into a crumpled nanotube. But tubes that hit lengthwise actually split into ribbons with ragged edges.
Hypervelocity impact tests are used mostly to simulate the impact of different projectiles on shields spacecraft
We were investigating possible applications for carbon nanotubes in space when we got this result. The effect was confirmed through molecular simulations.
Single-wall nanotubes do just the opposite; when the tube flattens the bottom wall hits the inside of the top wall
Ozden explained that the even distribution of stress along the belly-flopping nanotube which is many times longer than it is wide breaks carbon bonds in a line nearly simultaneously.
The researchers said 70 to 80 percent of the nanotubes in a pellet unzip to one degree or another.
Scientists shoot carbon nanotubes out of high-speed gun (w/video) More information: Unzipping Carbon nanotubes at High Impact.
Sehmus Ozden Pedro A s. Autreto Chandra Sekhar Tiwary Suman Khatiwada Leonardo Machado Douglas S. Galvao Robert Vajtai Enrique V. Barrera
#Scientists shoot carbon nanotubes out of high-speed gun (w/video)( Phys. org) What happens when you shoot multiwalled carbon nanotubes (MWCNTS) out of a gun onto an aluminum target at a velocity of more than 15000 mph?
Scientists finally have the answer. If a nanotube reaches the target at a 90â°angle (head-on) it will break
and deform quite drastically. However if it is parallel to the target upon impact the nanotube will unzip resulting in a 2d graphene nanoribbon.
This observation is unexpected since previous simulations have shown that nanotubes break into pieces when subjected to large mechanical forces.
Researchers Sehmus Ozden et al. at Rice university in Houston Texas US; the State university of Campinas in Campinas Brazil;
and the Indian Institute of Science in Bangalore India have published a paper on the results of their high-impact nanotube collision experiments in a recent issue of Nano Letters.
Because it was not possible to directly observe the impact due to the nanotubes'small size
and high speed the researchers analyzed the differences in the nanotubes using a transmission electron microscope before and after the impact to extract useful information about
Although each bundle of nanotubes (the pellet) was shot perpendicular to the target the individual randomly aligned nanotubes impacted the target at different angles.
At a 90â°impact angle the nanotubes deformed along the radial direction essentially being smashed like the front of a car in a head-on collision.
At a 45â°impact angle the nanotubes became partly deformed and partly unzipped. At a 0â°angle the nanotubes were unzipped completely
when shot at the aluminum target. The researchers explain that the unzipping occurs on the scale of femtoseconds.
In that short time many atoms along the side of the nanotube become stressed due to the impact resulting in the breaking of the carbon bonds in a straight line along the side of the nanotube.
Many of these atoms ended up being ejected from the nanotube rather than having their bonds neatly broken as in the 0â°impact angle scenario.
Unzipping carbon nanotubes to create 2d graphene nanoribbons is very useful in nanoscience but until now it has typically been achieved with chemical contaminants that leave back contaminants.
By demonstrating for the first time that nanotubes can be unzipped quickly through mechanical means the new study offers a clean-cut a clean chemical-free way to produce high-quality graphene nanoribbons.
As the researchers explained graphene nanoribbons have certain advantages over both nanotubes and graphene that make them attractive for applications.
They are superior to carbon nanotubes as their bandgap is more predictable. Also they are superior to graphene itself as graphene has no bandgap
Hybrid nanotube-graphene material promises to simplify manufacturing More information: Sehmus Ozden et al. Unzipping Carbon nanotubes at High Impact.
Nano Letters. DOI: 10.1021/nl501753 0
#Super-stretchable yarn is made of graphene A simple, scalable method of making strong, stretchable graphene oxide fibers that are scrolled easily into yarns
researchers from the USC Viterbi School of engineering describe how they have overcome a major issue in carbon nanotube technology by developing a flexible,
energy-efficient hybrid circuit combining carbon nanotube thin film transistors with other thin film transistors. This hybrid could take the place of silicon as the traditional transistor material used in electronic chips,
since carbon nanotubes are more transparent, flexible, and can be processed at a lower cost. Electrical engineering professor Dr. Chongwu Zhou and USC Viterbi graduate students Haitian Chen
and Jialu Zhang developed this energy-efficient circuit by integrating carbon nanotube (CNT) thin film transistors (TFT) with thin film transistors comprised of indium, gallium and zinc oxide (IGZO)."
"Before then, we were working hard to try to turn carbon nanotubes into n-type transistors and then one day,
Instead of working so hard to force nanotubes to do something that they are not good for,
"Carbon nanotubes are so small that they can only be viewed through a scanning electron microscope. This hybridization of carbon nanotube thin films and IGZO thin films was achieved by combining their types, p-type and n-type, respectively,
to create circuits that can operate complimentarily, reducing power loss and increasing efficiency. The inclusion of IGZO thin film transistors was necessary to provide power efficiency to increase battery life.
If only carbon nanotubes had been used, then the circuits would not be power-efficient. By combining the two materials,
Zhou likened the coupling of carbon nanotube TFTS and IGZO TFTS to the Chinese philosophy of yin and yang."
With this development, Zhou and his team have circumvented the difficulty of creating n-type carbon nanotube TFTS
and p-type IGZO TFTS by creating a hybrid integration of p-type carbon nanotube TFTS and n-type IGZO TFTS and demonstrating a large-scale integration of circuits.
Up to this point, all carbon nanotube-based transistors had a maximum number of 200 transistors.""We believe this is a technological breakthrough,
"The next step for Zhou and his team will be to build more complicated circuits using a CNT
"Zhou and Chen believe that carbon nanotube technology, including this new CNT-IGZO hybrid, will be commercialized in the next 5-10 years."
"I believe that this is just the beginning of creating hybrid integrated solutions, "said Zhou.""We will see a lot of interesting work coming up. g
#Charging portable electronics in 10 minutes Researchers at the University of California Riverside Bourns College of Engineering have developed a three-dimensional silicon-decorated cone-shaped carbon nanotube cluster architecture for lithium ion battery anodes that could enable charging of portable
In a paper Silicon Decorated Cone Shaped Carbon nanotube Clusters for Lithium ion battery Anode recently published in the journal Small UC Riverside researchers developed a novel structure of three-dimensional silicon decorated cone-shaped
carbon nanotube clusters architecture via chemical vapor deposition and inductively coupled plasma treatment. Lithium ion batteries based on this novel architecture demonstrate a high reversible capacity and excellent cycling stability.
One the seamless connection between graphene covered copper foil and carbon nanotubes enhances the active material-current collector contact integrity
High-resolution microscopy technique resolves individual carbon nanotubes under ambient condition c
#DNA NANOTECHNOLOGY places enzyme catalysis within an arm's length Using molecules of DNA like an architectural scaffold, Arizona State university scientists,
but Pint and Westover are confident that the rules that govern the load-bearing character of their design will carry over to other materials, such as carbon nanotubes and lightweight porous metals like aluminum.
The team created silicon dioxide (Sio2) nanotube anodes for lithium-ion batteries and found they had over three times as much energy storage capacity as the carbon-based anodes currently being used.
The paper,"Stable Cycling of Sio2 Nanotubes as High-performance Anodes for Lithium-Ion Batteries,"was published online in the journal Nature Scientific Reports.
There key finding was that the silicon dioxide nanotubes are extremely stable in batteries, which is important
Specifically, Sio2 nanotube anodes were cycled 100 times without any loss in energy storage capability and the authors are highly confident that they could be cycled hundreds more times.
The researchers are focused now on developed methods to scale up production of the Sio2 nanotubes in hopes they could become a commercially viable product t
This one packs an interconnected network of graphene and carbon nanotubes so tightly that it stores energy comparable to some thin-film lithium batteriesn area where batteries have held traditionally a large advantage.
A solution containing acid-oxidized single-wall nanotubes graphene oxide and ethylenediamine which promotes synthesis and dopes graphene with nitrogen is pumped through a flexible narrow reinforced tube called a capillary column and heated in an oven for six hours.
Sheets of graphene one to a few atoms thick and aligned single-walled carbon nanotubes self-assemble into an interconnected prorous network that run the length of the fiber.
High-performance low-cost ultracapacitors built with graphene and carbon nanotubes More information: Paper: Scalable synthesis of hierarchically structured carbon nanotuberaphene fibres for capacitive energy storage dx. doi. org/10.1038/nnano. 2014.9 n
#Pillared Graphene structures Gain Strength, Toughness and Ductility In a newly published study, scientists from Rice university reveal that putting nanotube pillars between sheets of graphene could create hybrid structures with a unique balance of strength, toughness
Carbon nanomaterials are common now as flat sheets, nanotubes and spheres, and theye being eyed for use as building blocks in hybrid structures with unique properties for electronics,
particularly between carbon nanotubes and graphene, would affect the final hybrid properties in all directions. They found that introducing junctions would add extra flexibility
Carbon nanotubes are rolled-up arrays of perfect hexagons of atoms; graphene is a rolled out sheet of the same.
the way the atoms are arranged can influence all those properties. ome labs are actively trying to make these materials or measure properties like the strength of single nanotubes and graphene sheets,
and quantitatively predict the properties of hybrid versions of graphene and nanotubes. These hybrid structures impart new properties
and functionality that are absent in their parent structures graphene and nanotubes. To that end the lab assembled three-dimensional computer models of illared graphene nanostructures, akin to the boron nitride structures modeled in a previous study to analyze heat transfer between layers. his time we were interested in a comprehensive understanding of the elastic and inelastic properties
Shahsavari said. e compared our 3-D hybrid structures with the properties of 2-D stacked graphene sheets and 1-D carbon nanotubes.
The latter allows pillared graphene to exhibit remarkable toughness along out-of-plane directions, a feature that is not possible in 2-D stacked graphene sheets or 1-D carbon nanotubes,
Turning the nanotubes in a way that forced wrinkles in the graphene sheets added further flexibility and shear compliance,
one that includes carbon nanotubes. Now Fraunhofer has accomplished both feats, and with the most basic device imaginable:
The idea is to mix nanotubes into a fluid to create a slurry, lay down a film just a few micrometers thick on a suitable substrate,
The heat-generating resistance comes mainly from the passage of current through gaps between the nanotubes.
3d Bioprinted Carbon nanotubes Used to Stimulate Bone Regrowth How do you 3d print bone? A couple of years ago,
if you add carbon nanotubes to the mix to create a 3d electrical network within the bone tissue,
and scaffolds with the required shapes and sizes. he carbon nanotubes (or CNT) were added to the bioprintable material mixture to create a hree-dimensional electrical conducting network all through the volume of the scaffold,
CNTS are basically one-atom-thick graphene sheets rolled up onto themselves in order to form very long filaments with diameters of only a few nanometers. n this sense,
by adding conducting CNTS into the bioprinted polymer and mineral prosthetic bone implant, you can stimulate the regrowth of the actual bone cells.
Perhaps one of the most curious aspects is that bioprinting CNTS created no additional difficulties,
the addition of the CNTS was performed and reaching a proper dispersion took a bit of stirring time. ercedes
#Breakthrough, Low-cost Method to Build DNA NANOTUBES Block By Block Researchers at Mcgill University have developed a new,
low-cost method to build DNA NANOTUBES block by block a breakthrough that could help pave the way for scaffolds made from DNA strands to be used in applications such as optical and electronic devices or smart drug-delivery systems.
have constructed previously nanotubes using a method that relies on spontaneous assembly of DNA in solution.
we can now build long nanotubes block by block, said Amani Hariri, a Phd student in Mcgill Department of chemistry and lead author of the study. y using a fluorescence microscope we can further visualize the formation of the tubes at each stage of assembly,
The custom-built assembly technique developed through this collaboration ives us the ability to monitor the nanotubes as wee building them,
The resulting esigner nanotubes she adds, promise to be far cheaper to produce on a large scale than those created with so-called DNA origami,
Tungstenglass is based a borosilicate glass that is infused with tungsten and carbon nanotubes. The composition enhances the protective qualities of the glass by providing improved resistance to impact and scratching,
while because of the electrical properties of the Tungsten and Carbon nanotubes the electrical conductivity is improved making for a more sensitive surface for Human fingers."
The company has taken renewable plant oils and added Tungsten and Carbon nanotubes to the oil blend.
The Organic Bio-Based Motor oil patent describes the assembly process for blending Nanotubes and various highly viscous all natural plant oils to form Nanosave N1-Organic.
#Inner Space of Carbon nanotubes Could act as a Template for Synthesis of Linear-Chain Nanodiamonds The inner space of carbon nanotubes can act as a template for the synthesis of nanodiamond-like carbon chains.
Hisanori Shinohara from Nagoya University in Japan and his colleagues have developed a method that uses carbon nanotubes as a reaction vessel for the templated polymerization of linear-chain nanomaterials.
and with each other inside the carbon nanotubes, "the authors write. And:""Depending on the inner diameter of the carbon nanotubes,
the inserted species can either be transformed into the linear-chain polymers or into amorphous carbon."
the formed carbon nanotubes filled with the nanodiamondoid polymer look like macaroni filled with spaghetti. In order to extract the inner polymer,
#Researchers Build Optical Rectennas Using Carbon nanotubes and Tiny Rectifiers Optical rectennas, antenna-rectifier diodes that convert light into DC current, have been built using multiwall carbon nanotubes with integrated nanoscale rectifiers.
The produced optical rectennas hold promise as photodetectors that do not require cooling and energy harvesters that could be used for conversion of waste heat to electricity.
The carbon nanotubes in the devices function as antennas for capturing light. When the light waves strike the nanotube antennas,
an oscillating charge is created that travels through the rectifier devices. A small direct current (DC) is created
-Prof Baratunde Cola, Georgia Tech The team employed nanoscale fabrication techniques alongside metallic multiwall carbon nanotubes to build devices that utilized light's wave nature rather than its particle nature.
the researchers grew forests of vertically aligned carbon nanotubes on a conductive substrate. Atomic layer chemical vapour deposition was used to in sulate the nanotubes with a coating of aluminum oxide.
Optically transparent thin calcium layers were deposited then using physical vapor deposition over the nanotube forest.
A potential difference of 2ev was achieved which is sufficient for ejecting electrons out of the carbon nanotube antennas upon the absorption of visible light Light in the form of oscillating waves interacts with nanotubes after going through the calcium-aluminum electrode.
The nanotube tips have metal-insulator-metal junctions that work as rectifiers. These rectifiers switch on and off at time intervals in the femtosecond range.
This means the electrons flow in one direction towards the top electrode. The 10nm diode functions at such a high frequency due to the ultra-low capacitance,
allowing multiple conduction channels in the carbon nanotubes, and reducing the structural resistance. e think we can reduce the resistance by several orders of magnitude just by improving the fabrication of our device structures,
'While other designs for space elevators have involved complex designs using graphene or carbon nanotubes, the Thoth design reportedly uses inflatable sections
The secret of its design is a scattering of billions of carbon'nanotubes'-microscopic hollow carbon rods.
Putting pressure on the skin squeezes the nanotubes closer together and enables them to conduct electricity.
"Some researchers have wanted to make transistors out of carbon nanotubes but the problem is that they grow in all sorts of directions,
which relies on materials called carbon nanotubes, allows scientists to build the chip in three dimensions. The 3d design enables scientists to interweave memory,
Carbon nanotubes To get around this issue Shulaker and his advisers at Stanford university, Subhasish Mitra and H.-S. Philip Wong, looked to a completely different material:
carbon nanotubes, or miniscule mesh rods made of carbon atoms, which can be processed at low temperatures. Carbon nanotubes (CNTS) have electrical properties similar to those of conventional silicon transistors.
In a head-to-head competition between a silicon transistor and a CNT transistor,"hands down, the CNT would win,
"Shulaker told Live Science.""It would be a better transistor; it can go faster; it uses less energy."
"However, carbon nanotubes grow in a disorderly manner, "resembling a bowl of spaghetti, "which is no good for making circuits,
As such, the researchers developed a method to grow nanotubes in narrow grooves, guiding the nanotubes into alignment.
But there was another hurdle. While 99.5 percent of the nanotubes become aligned, a few stragglers will still be out of position.
To solve this problem, the researchers figured out that drilling holes at certain spots within the chip can ensure that even a chip with wayward tubes would work as expected.
while most CNTS have the properties of a semiconductor (like silicon), a few act just like an ordinary conducting metal,
As a remedy, Shulaker and his colleagues essentially"turn off"all the semiconducting CNTS, leaving huge jolts of current to circulate through the remaining conducting nanotubes.
The high current heats up and breaks down only the conducting nanotubes, which blow like nanoscale fuses,
Shulaker said. In 2013, the team built a CNT COMPUTER which they described in the journal Nature.
That computer, however, was slow and bulky, with relatively few transistors. Now, they have created a system for stacking memory and transistor layers,
"Some researchers have wanted to make transistors out of carbon nanotubes, but the problem is that they grow in all sorts of directions,
Graphene-nanotube hybrid switches But together, these two materials make a workable digital switch, which is the basis for controlling electrons in computers, phones, medical equipment and other electronics.
Yoke Khin Yap, a professor of physics at Michigan Technological University, has worked with a research team that created these digital switches by combining graphene and boron nitride nanotubes.
the nanotubes are made like straws of boron and nitrogen. Yap and his team exfoliate graphene
Then they can grow the nanotubes up and through the pinholes. Meshed together like this, the material looks like a flake of bark sprouting erratic, thin hairs."
and the atomic structure in the nanotubes halts electric currents. This disparity creates a barrier, caused by the difference in electron movement as currents move next to and past the hairlike boron nitride nanotubes.
These points of contact between the materials--called heterojunctions--are what make the digital on/off switch possible."
the use of graphene and nanotubes bypasses those problems. In addition, the graphene and boron nitride nanotubes have the same atomic arrangement pattern,
or lattice matching. With their aligned atoms, the graphene-nanotube digital switches could avoid the issues of electron scattering."
"You want to control the direction of the electrons, "Yap explains, comparing the challenge to a pinball machine that traps,
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