a tiny hole in a ceramic sheet that holds electrolyte to carry the electrical charge between nanotube electrodes at either end.
Adrian Bachtold, together with Marc Dykman (Michigan University), report on an experiment in which a carbon nanotube mechanical resonator exhibits quality factors of up to 5 million,
30 times better than the best quality factors measured in nanotubes to date. Imagine that the host of a dinner party tries to get his guests'attention by giving a single tap of his oyster spoon on his crystal glass.
Nowadays, carbon nanotube mechanical resonators are in demand because of their extremely small size and their outstanding capability of sensing objects at the nanoscale.
Like a guitar string or a tightrope, a carbon nanotube resonator consists of a tiny, vibrating bridge-like (string) structure with typical dimensions of 1#m in length and 1nm in diameter.
and because of this trend it was unthinkable that nanotubes could exhibit giant quality factors. The giant quality factors that ICFO researchers have measured have not been observed before in nanotube resonators mainly
because their vibrational states are extremely fragile and easily perturbed when measured. The values detected by the team of scientists was achieved through the use of an ultra-clean nanotube at cryostat temperatures of 30mk(-273.12 Celsius-colder than the temperature of outerspace!
and by employing an ultra-low noise method to detect minuscule vibrations quickly while reducing as much as possible the electrostatic noise.
since"nanotube resonators are enormously sensitive to surrounding electrical charges that fluctuate constantly. This stormy environment strongly affects our ability to capture the intrinsic behavior of nanotube resonators.
For this reason, we had to take a very large number of snapshots of the nanotube's mechanical behavior.
Only a few of these snapshots captured the intrinsic nature of the nanotube's dynamics, when the storm momentarily relented.
During these short quiet moments, the nanotube revealed its ultra-high quality factor to us"."With the discovery of such high quality factors from this study, ICFO scientists have opened a whole new realm of possibilities for sensing applications,
and quantum experiments. For instance, nanotube resonators might be used to detect individual nuclear spins, which would be an important step towards magnetic resonance imaging (MRI) with a spatial resolution at the atomic level.
For the moment, Adrian Bachtold comments that"achieving MRI at the atomic level would be fantastic. But, for this, we would first have to solve various technological problems that are extremely challenging. n
#Better bomb-sniffing technology with new detector material University of Utah engineers have developed a new type of carbon nanotube material for handheld sensors that will be quicker
A carbon nanotube is a cylindrical material that is a hexagonal or six-sided array of carbon atoms rolled up into a tube.
The new kind of nanotubes also could lead to flexible solar panels that can be rolled up and stored or even"painted"on clothing such as a jacket,
they alter the electrical current through the nanotube materials, signaling the presence of any of those substances,
and monitor the current through the nanotube,"says Zang, a professor with USTAR, the Utah Science Technology and Research economic development initiative."
or toxic chemicals caught by the nanotube, you will see an increase or decrease in the current."
"By modifying the surface of the nanotubes with a polymer, the material can be tuned to detect any of more than a dozen explosives,
the Utah carbon nanotube technology has four advantages s
#A quantum leap in nanoparticle efficiency (Phys. org) New research has unlocked the secrets of efficiency in nanomaterials that is materials with very tiny particles
which drives the nanotubes through the gradient. The nanotubes move through the gradient until their density matches that of the gradient.
The result is that the nanotubes form separated bands in the centrifuge tube by density.
Since the density of the nanotube is a function of its diameter this method allows separation by diameter.
One property that distinguishes these materials from traditional semiconductors like silicon is that they are mechanically flexible.
Breakthrough for carbon nanotube solar cell l
#See-through one-atom-thick carbon electrodes powerful tool to study brain disorders Researchers from the Perelman School of medicine and School of engineering at the University of Pennsylvania and The Children's Hospital of Philadelphia have used graphene
The Center for Neuroengineering and Therapeutics (CNT) under the leadership of senior author Brian Litt Phd has solved this problem with the development of a completely transparent graphene microelectrode that allows for simultaneous optical imaging
Kuzum emphasizes that the transparent graphene microelectrode technology was achieved through an interdisciplinary effort of CNT and the departments of Neuroscience Pediatrics and Materials science at Penn and the division of Neurology at CHOP.
The combination of nanocarbon and sulfur is effective at overcoming the insulating nature of sulfur for lithium sulfur batteries."
"Due to excellent electrical conductivity, mechanical strength and chemical stability, nanocarbon materials have played an essential role in the area of advanced energy storage,
Recently, scientists from Tsinghua University have created a freestanding carbon nanotube paper electrode with high sulfur loading for lithium-sulfur batteries.
"We select carbon nanotube (CNT) as the building block",Qiang told Phys. org, "CNTS are one of the most efficient and effective conductive fillers for electrode.
We selected short multi-walled CNTS (MWCNTS) with lengths of 10-50 m as the shortrange electrical conductive network to support sulfur,
as well as super long CNTS with lengths of 1000-2000 m from vertically aligned CNTS (VACNTS) as both long-range conductive networks and inter-penetrated binders for the hierarchical freestanding paper electrode.""
""We develop a bottom-up routine in which sulfur was dispersed firstly well into the MWCNT network to obtain MWCNT@S building blocks
and then MWCNT@S and VACNTS were assembled into macro-CNT-S films via the dispersion in ethanol followed by vacuum filtration",Zhe Yuan,
"Such sulfur electrodes with hierarchical CNT scaffolds can accommodate over 5 to 10 times the sulfur species compared with conventional electrodes on metal foil current collectors
"The areal capacity can be increased further to 15.1 mah cm-2 by stacking three CNT-S paper electrodes, with an areal sulfur loading of 17.3 mg cm-2 as the cathode in a Li
which is also favorable for graphene, CNT-graphene, CNTMETAL oxide based flexible electrodes, "Qiang said."
Electronics based on carbon especially carbon nanotubes (CNTS) are emerging as successors to silicon for making semiconductor materials.
and optimization of the device which is based on a phosphor screen and single-walled carbon nanotubes as electrodes in a diode structure.
They assembled the device from a mixture liquid containing highly crystalline single-walled carbon nanotubes dispersed in an organic solvent mixed with a soap-like chemical known as a surfactant.
Under a strong electric field the cathode emits tight high-speed beams of electrons through its sharp nanotube tips a phenomenon called field emission.
We have found that a cathode with highly crystalline single-walled carbon nanotubes and an anode with the improved phosphor screen in our diode structure obtained no flicker field emission current and good brightness homogeneity Shimoi said.
Highly crystalline single-walled carbon nanotubes (HCSWCNT) have nearly zero defects in the carbon network on the surface Shimoi explained.
The resistance of cathode electrode with highly crystalline single-walled carbon nanotube is very low. Thus the new flat-panel device has compared smaller energy loss with other current lighting devices
and height of the nanotubes the researchers were able to achieve a fluid flow that enabled an operating ion current at very near the theoretical limit.
To control the nanotubes'growth the researchers first cover the emitter array with an ultrathin catalyst film
The nanotubes grow up under the catalyst particles which sit atop them until the catalyst degrades.
Using their nanotube forest they're able to get the devices to operate in pure ion mode
#New nanomaterial introduced into electrical machines Lappeenranta University of Technology in Finland has constructed the world's first prototype electrical motor using carbon nanotube yarn in the motor windings.
carbon nanotube yarn. The presently most electrically conductive carbon nanotube yarn replaces usual copper wires in the windings.
The motor prototype is built by the LUT Electrical engineering group as a start towards lightweight efficient electric drives.
In the near future carbon nanotube fibers have potential to significantly enhance the performance and energy efficiency of electrical machines.
The best carbon nanotubes (CNTS) have demonstrated conductivities far beyond those of the best metals. Thus future windings made of CNTS may have a double conductivity compared with the present-day copper windings.
In order to make CNTS easy to manipulate they are spun to form multifiber yarn. If we keep the electrical machine design parameters unchanged and only replace copper with future carbon nanotube wires it is possible to reduce the Joule losses in the windings to half of the present-day machine losses.
Carbon nanotube wires are significantly lighter than copper and also environmentally friendlier. Therefore replacing copper with nanotube wires should significantly reduce the CO2 EMISSIONS related to the manufacturing
and operating of electrical machines. Furthermore the machine dimensions and masses could be reduced. The motors could also be operated in significantly higher temperatures than the present ones says Professor Juha Pyrh nen who has led the design of the prototype at LUT.
No definite upper limit for the conductivity Traditionally the windings in electrical machines are made of copper which has the second best conductivity of metals at room temperature.
Despite the high conductivity of copper a large proportion of the electrical machine losses occur in the copper windings.
The carbon nanotube yarn does not have a definite upper limit for conductivity (e g. values of 100 MS/m have already been measured.
The prototype motor uses carbon nanotube yarns spun and converted into an isolated tape by a Japanese-Dutch company Teijin Aramid
We expect that in the future the conductivity of carbon nanotube yarns could be even three times the practical conductivity of copper in electrical machines.
Carbon nanotube fibers outperform coppe e
#New absorber will lead to better biosensors Biological sensors or biosensors are like technological canaries in the coalmine.
#Nanoparticles accumulate quickly in wetland sediment (Phys. org) A Duke university team has found that nanoparticles called single-walled carbon nanotubes accumulate quickly in the bottom sediments of an experimental wetland setting an action they say could indirectly damage the aquatic food chain.
But the researchers warn that based on their previous research the tendency for the nanotubes to accumulate in sediment could indirectly damage the aquatic food chain in the long term
Ferguson and his colleagues dosed the mesocosms with single-walled carbon nanotubes and measured their concentrations in the water soil and living organisms during the course of a year.
Fate of single walled carbon nanotubes in wetland ecosystems. Schierz A. Espinasse B. Wiesner M. R. Bisesi J. H. Sabo-Attwood T. Ferguson P. L. Environmental science:
#Nanotube cathode beats large pricey laser Scientists are a step closer to building an intense electron beam source without a laser.
Using the High-Brightness Electron Source Lab at DOE's Fermi National Accelerator Laboratory a team led by scientist Luigi Faillace of Radiabeam Technologies is testing a carbon nanotube cathode about the size of a nickel
Tests with the nanotube cathode have produced beam currents a thousand to a million times greater than the one generated with a large pricey laser system.
While carbon nanotube cathodes have been studied extensively in academia Fermilab is the first facility to test the technology within a full-scale setting.
The tested nanotube cathode requires no laser: it only needs the electric field already generated by an accelerator to siphon the electrons off a process dubbed field emission n
and the nanotubes have outstanding electrical conductivity, and they can effectively separate and transport electrical charges generated from solar energy.
and charge transport at very low nanotube loadings, thereby strongly reducing materials costs o
#Scientists improve microscopic batteries with homebuilt imaging analysis (Phys. org) In a rare case of having their cake
#Nanotubes help healing hearts keep the beat (Phys. org) Carbon nanotubes serve as bridges that allow electrical signals to pass unhindered through new pediatric heart-defect patches invented at Rice university and Texas Children's Hospital.
and chemical engineer and chemist Matteo Pasquali created the patches infused with conductive single-walled carbon nanotubes.
The nanotubes overcome a limitation of current patches in which pore walls hinder the transfer of electrical signals between cardiomyocytes the heart muscle's beating cells
Nanotubes can fix that and Jacot who has a joint appointment at Rice and Texas Children's took advantage of the surrounding collaborative research environment.
We thought nanotubes could be integrated easily. Nanotubes enhance the electrical coupling between cells that invade the patch helping them keep up with the heart's steady beat.
When cells first populate a patch their connections are compared immature with native tissue Jacot said.
but the nanotubes forge a path around the obstacles. Jacot said the relatively low concentration of nanotubes 67 parts per million in the patches that tested best is key.
Earlier attempts to use nanotubes in heart patches employed much higher quantities and different methods of dispersing them.
Jacot's lab found a component they were already using in their patches#chitosan#keeps the nanotubes spread out.
Chitosan is amphiphilic meaning it has hydrophobic and hydrophilic portions so it can associate with nanotubes (which are hydrophobic)
and keep them from clumping. That's what allows us to use much lower concentrations than others have tried.
and get to it with the fewest nanotubes possible he said. We can do this if we control dispersion well and use high-quality nanotubes.
The patches start as a liquid. When nanotubes are added the mixture is shaken through sonication to disperse the tubes
which would otherwise clump due to Van der waals attraction. Clumping may have been an issue for experiments that used higher nanotube concentrations Pasquali said.
The material is spun in a centrifuge to eliminate stray clumps and formed into thin fingernail-sized discs with a biodegradable polycaprolactone backbone that allows the patch to be sutured into place.
As a side benefit nanotubes also make the patches stronger and lower their tendency to swell
This is a good example of how it's much better for an application person like Dr. Jacot to work with experts who know how to handle nanotubes rather than trying to go solo as many do said he.
Biocompatible Carbon nanotube#Chitosan Cardiac Scaffold Matching the Electrical conductivity of the Heart. Seokwon Pok Flavia Vitale Shannon L. Eichmann Omar M. Benavides Matteo Pasquali and Jeffrey G Jacot ACS Nano Just Accepted Manuscript DOI:
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.
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,
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."
#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,
Single-walled carbon nanotube (SWNT which can be considered as a seamlesscylinder formed by rolling a piece of graphene,
"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,
#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
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.
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.
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.
when you shoot multiwalled carbon nanotubes (MWCNTS) out of a gun onto an aluminum target at a velocity of more than 15000 mph?
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.
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;
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.
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.
Hybrid nanotube-graphene material promises to simplify manufacturing More information: Sehmus Ozden et al. Unzipping Carbon nanotubes at High Impact.
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,
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)."
Instead of working so hard to force nanotubes to do something that they are not good for,
This hybridization of carbon nanotube thin films and IGZO thin films was achieved by combining their types, p-type and n-type, respectively,
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.
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,
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
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.
#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,
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
Turning the nanotubes in a way that forced wrinkles in the graphene sheets added further flexibility and shear compliance,
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