The metallic nanostructures use surface plasmons waves of electrons that flow like a fluid across metal surfaces.
Researchers use aluminum nanostructures for photorealistic printing of plasmonic color palettes More information: Zheng B. Y. Wang Y. Nordlander P. and Halas N. J. 2014) Color-Selective and CMOS-Compatible Photodetection Based on Aluminum Plasmonics.
but a new way of working with copper nanowires and a PVA"nano glue"could be a game-changer.
Previous success in the field of ultra-lightweight"aerogel monoliths"has relied largely on the use of precious gold and silver nanowires.
but ours are made of ultra fine copper nanowires, using a fabrication process called freeze drying,
"Despite its conductivity, copper's tendency to oxidation and the poor mechanical stability of copper nanowire aerogel monoliths mean its potential has been unexplored largely.
"The conductivity can be tuned simply by adjusting the loading of copper nanowires, "he said.""A low loading of nano wires would be appropriate for a pressure sensor
the researchers noted that devices using their copper-based aerogels were not quite as sensitive as those using gold nanowires,
is produced by plasmonic-enhanced optical scattering of the nanostructures. The subwavelength distance offers certain advantages.
We believe that it will also prompt new experiments focusing on the dynamical properties of the atoms at nanostructures,
#Bacterial nanowires: Not what we thought they were For the past 10 years scientists have been fascinated by a type of electric bacteria that shoots out long tendrils like electric wires using them to power themselves
Today a team led by scientists at USC has turned the study of these bacterial nanowires on its head discovering that the key features in question are not pili as previously believed
Scientists had suspected long that bacterial nanowires were pili Latin for hair which are hairlike features common on other bacteria allowing them to adhere to surfaces
Given the similarity of shape it was easy to believe that nanowires were pili. But Moh El-Naggar assistant professor at the USC Dornsife College of Letters Arts and Sciences says he was always careful to avoid saying that he knew for sure that's what they were.
with bacterial nanowires. This latest study will be published online by the Proceedings of the National Academy of Sciences on August 18.
During the formation of nanowires scientists noted an increase in the expression of electron transport genes but no corresponding increase in the expression of pilin genes.
what nanowires weren't the team next needed to figure out what they actually were. El-Naggar credits Sahand Pirbadian USC graduate student with devising an ingenious yet simple strategy to make the discovery.
By depriving the bacteria of oxygen the researchers were able to force the bacteria to stretch out their nanowires on command allowing the process to be observed in real time.
and specific proteins researchers were able to take video of the nanowires reaching out confirming that they were based on membrane and not pili at all.
Generating videos of the nanowires stretching out required new methods to simultaneously label multiple features keep a camera focused on the wriggling bacteria and combine the optical techniques with atomic force microscopy to gain higher resolution.
and figure out the right conditions for the bacteria to produce nanowires Pirbadian said. We had to go back
Once we were able to induce nanowire growth we started analyzing their composition and structure
Shewanella oneidensis MR-1 nanowires are outer membrane and periplasmic extensions of the extracellular electron transport components PNAS www. pnas. org/cgi/doi/10.1073
#Pentagonal nanorods show catalytic promise Pentagonal nanorods have a unique morphology that confers interesting compositional
Now, researchers in Singapore have developed a simple chemical process to grow uniform pentagonal nanorods composed of gold and copper.
"We successfully synthesized goldopper pentagonal nanorods with controlled size and composition by a seed-mediated growth route,"explains lead researcher Jackie Ying from the A*STAR Institute of Bioengineering and Nanotechnology.
To create the nanorods, the team placed the gold seeds in a solution containing a copper precursor and applied heat a process that produced nearly uniform pentagonal nanorods.
Ying's team showed that they could control the length of these nanorods by changing the amount of gold seeds added to the copper precursor.
Adding a 1: 1 ratio of gold to copper produced nanorods that grew approximately 15 nanometers in length while a 1: 2 ratio produced nanorods approximately 19 nanometers long,
and a 1: 3 ratio produced nanorods approximately 24 nanometers long. The diameter of the nanorods remained the same,
however, regardless of the ratio of metals used. The ability to control the size and composition of the nanorods means it is easier to control the properties of the bimetallic goldopper nanoparticles compared to nanoparticles made of just one metal,
Yang explains. Next, the team evaluated the catalytic activity of these goldopper nanorods in a carbonitrogen-bond-forming reactionhe direct alkylation of an amine using an alcohol."
"This hydrogen-borrowing strategy is an attractive synthetic method for the C bond formation as it is an environmentally friendly process
which produces only water as a byproduct, "says Ying. The nanorods were examined as catalysts for this reaction using the model substrates p-toluene sulphonamide and benzyl alcohol."
"Our heterogeneous catalyst showed higher catalytic activity toward the C coupling reaction and better recyclability compared to commercially available catalysts,
Her team now plans to use the nanorods as seeds themselves to synthesize nanoparticles comprised of a goldopper core surrounded by a shell of another material, such as platinum, for energy applications
Through highly precise control of the geometry of the nanostructures and using Raman spectroscopy an ultra-sensitive molecular identification technique the light can be trapped between the mirrors allowing the researchers to'fingerprint'individual molecules.
or stretched creates a voltage by converting energy from motion into electrical energy, in the form of nanorods.
The nanorods can be coated onto various surfaces in different locations making the energy harvesting quite versatile.
the nanorods then generate a high voltage. The nanorods respond to vibration and movement created by everyday sound,
such as our voices. Electrical contacts on both sides of the rods are used then to harvest the voltage to charge a Phone in order to make it possible to produce these nanogenerators at scale
whereby they could spray on the nanorod chemicals almost like nanorod graffiti to cover a plastic sheet in a layer of zinc oxide.
the nanorods grew all over the surface of the sheet. Secondly, gold is used traditionally as an electrical contact
His team has made ultrathin nanowires that can monitor and influence what goes on inside cells.
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:
into a silicon nanowire. With this new method of producing hybrid nanowires, very fast and multifunctional processing units can be accommodated on a single chip in the future.
The research results will be published in the journal Nano Research. Nano-optoelectronics are considered the cornerstone of future chip technology,
they integrated compound semiconductor crystals made of indium arsenide (Inas) into silicon nanowires, which are suited ideally for constructing increasingly compact chips.
This integration of crystals was the greatest obstacle for such"hetero-nanowires"until now: beyond the nanometer range, crystal lattice mismatch always led to numerous defects.
and embedding of the Inas crystals into the nanowires for the first time. Implanted atoms form crystals in the liquid-Phase in order to carry out this process,
maintains the form of the liquid nanowire, "explains HZDR scientist Dr. Slawomir Prucnal, "while the implanted atoms form the indium arsenide crystals."
"In the next step, the scientists want to implement different compound semiconductors into Silicon nanowires and also optimize the size and distribution of the crystals a
One of the most promising developments involves layering anti-reflective nanostructures on top of an anti-glare surface.
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.
Recently, there has been a lot of interest in fabricating metal-based nanotextured surfaces that are preprogrammed to alter the properties of light in a specific way after incoming light interacts with it,
how they want their nanostructure to modify light.""The researchers developed a novel, metal, pillar-bowtie nanoantenna (p-BNA) array template on 500-nanometer tall glass pillars (or posts.
One possibility is to use hybrid solar cells that combine silicon nanowires with low-cost, photoresponsive polymers. The high surface area and confined nature of nanowires allows them to trap significant amounts of light for solar cell operations.
Unfortunately, these thin, needle-like structures are very fragile and tend to stick together when the wires become too long.
Now, findings by Xincai Wang from the A*STAR Singapore Institute of Manufacturing Technology and co-workers from Nanyang Technological University could turn the tables on silicon nanowires by improving the manufacturing of silicon'nanoholes'arrow cavities carved into silicon wafers
Nanoholes are particularly effective at capturing light because photons can ricochet many times inside these openings until absorption occurs.
One significant problem, notes Wang, is control of the initial stages of nanohole formation crucial period that can often induce defects into the solar cell.
'maskless'approach to producing nanoholes using silver nanoparticles. First, they deposited a nanometer-thin layer of silver onto a silicon wafer
nanohole-infused silicon surface (see image). The team analyzed the solar cell activity of their nanohole interfaces by coating them with a semiconducting polymer and metal electrodes.
Their experiments revealed a remarkable dependence on nanohole depth: cavities deeper than one micrometer showed sharp drops in power conversion efficiency from a maximum of 8. 3 per cent due to light scattering off of rougher surfaces and higher series
resistance effects.""Our simple process for making hybrid silicon nanohole devices can successfully reduce the fabrication costs
which impede the solar cell industry, "says Wang.""In addition, this approach can be transferred easily to silicon thin films to develop thin-film siliconolymer hybrid solar cells with even higher efficiency. e
along with Dr. Seok-In Na at Chonbuk National University and Dr. Byoung Gak Kim at KRICT synthesized carbon nanosheets similar to graphene using polymer
The research outcome was introduced in Nanoscale a journal of Royal Society of Chemistry in the UK under the title of One-step Synthesis of Carbon Nanosheets Converted from a Polycylic Compound
The research team developed carbon nanosheet in a two-step process which consists of coating the substrate with a plymer solution and heating.
The carbon nanosheet can be mass-produced in a simpler process while having high quality since the new process bypasses the steps that are prone to formation of defects such as elimination of the metal substrate or transfer of graphene to another board.
#Shrinky Dinks close the gap for nanowires How do you put a puzzle together when the pieces are too tiny to pick up?
to close the gap between nanowires in an array to make them useful for high-performance electronics applications.
Nanowires are extremely fast, efficient semiconductors, but to be useful for electronics applications, they need to be packed together in dense arrays.
Researchers have struggled to find a way to put large numbers of nanowires together so that they are aligned in the same direction and only one layer thick."
"Chemists have done already a brilliant job in making nanowires exhibit very high performance. We just don't have a way to put them into a material that we can handle,
people can make nanowires and nanotubes using any method they like and use the shrinking action to compact them into a higher density."
"The researchers place the nanowires on the Shrinky Dinks plastic as they would for any other substrate,
but then shrink it to bring the wires much closer together. This allows them to create very dense arrays of nanowires in a simple, flexible and very controllable way.
The shrinking method has added the bonus of bringing the nanowires into alignment as they increase in density.
Nam's group demonstrated how even wires more than 30 degrees off-kilter can be brought into perfect alignment with their neighbors after shrinking."
and the low cost of plastic could have a huge impact on nanowire assembly and processing for applications."
For example, experiments have shown that film made of packed nanowires has properties that differ quite a bit from a crystal thin film."
made of densely packed nanowires, that could harvest energy from light much more efficiently than traditional thin-film solar cells s
of Nanotechology) and their colleagues have succeeded now in producing a novel type of nanofiber whose highly ordered and porous structure gives it an extraordinarily high surface-to-volume ratio.
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.
Ozden said the process eliminates the need to clean chemical residues from nanoribbons produced through current techniques.
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
#Diamond plates create nanostructures through pressure not chemistry You wouldn't think that mechanical forcehe simple kind used to eject unruly patrons from bars,
and original method uses simple pressure kind of high-tech embossingo produce finer and cleaner results in forming silver nanostructures than do chemical methods,
when applied to nanoparticle arrays, forms new nanostructures with tunable properties.""There is a great potential market for this technology,
Propinquity creates conditions that produce nanorods, nanowires and nanosheets at chosen thicknesses and lengths rather than the one-size-fits-all output of a chemical process, with no environmentally harmful residues.
While experiments reported in the paper were performed with silverhe most desirable metal because it is the most conductive,
and mechanically stable nanostructures that no longer need restraining surfaces. These cannot be manufactured using current chemical methods.
composition and phase orientation of the initial nanoparticle arrays, a variety of nanostructures or nanocomposites and 3-D interconnected networks are achievable.
#Eco-friendly versatile nanocapsules developed The Institute for Basic Science (IBS) has announced that the Centre for Self-assembly
and Complexity have succeeded in developing a new technology that introduces metal nanoparticles on the surface of polymer nanocapsules made of cucurbit 6 uril.
The researchers have found that using polymer nanocapsules made of cucurbit 6 uril and metal salts can serve as a versatile platform where equal sized metal nanoparticles can be distributed evenly on the surface of the polymer nanocapsules.
Cucurbit 6 uril has properties which strongly and selectively recognize organic and inorganic chemical species. This makes it possible to use it as a protecting agent
The metal nanoparticle-decorated polymer nanocapsules exhibit the following properties in water: high stability for up to 6 months;
For example, the lotus can realize the self-cleaning effect using its micro/nanocomposite structure. The water striders can walk easily
and freely on the water surface via the special micro-and nanostructure on their legs.
Recently, Jiang's group focused on the confined water in one dimensional nanostructure materials. The study examined the confined water on the outer surfaces of one dimensional nano-structured materials including spider silk and cactus thorn,
and cactus thorn showed the confined water collection on these one dimensional nanostructures was helpful in solving the shortage of freshwater resources.
#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
Adding silver nanorods to the graphene film would increase the conductivity to the same as copper,
Quantum dots are novel nanostructures that can become the basis of the next generation of solar cells capable of squeezing additional electricity out of the extra energy of blue and ultraviolet photons.
A new study conducted within the Center for Advanced Solar Photophysics demonstrates that appropriately engineered core/shell nanostructures made of lead selenide
and should be realizable with other combinations of materials and/or nanostructure geometries. Jeff Pietryga lead CASP chemist says Further enhancement in carrier multiplication should be possible by combining this new approach with other demonstrated means for increasing multicarrier yields such as by using shape-control
(as in nanorods) and/or materials in which cooling is already naturally slower like Pbte.
Applied together these strategies might provide a practical route to nanostructures exhibiting carrier multiplication performance approaching the limits imposed by energy conservation n
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
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