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
Miniature all-solid-state heterostructure nanowire Li-ion batteries as a tool for engineering and structural diagnostics of nanoscale electrochemical processes.
The researchers have built a novel nanostructure that offers a new platform for the development of highly stable and reliable nanoscale memory devices.
#New research points to graphene as a flexible low-cost touchscreen solution New research published today in the journal Advanced Functional Materials suggests that graphene-treated nanowires could soon replace current touchscreen technology
Researchers from the University of Surrey and AMBER the materials science centre based at Trinity college Dublin have demonstrated now how graphene-treated nanowires can be used to produce flexible touchscreens at a fraction of the current cost.
Using a simple scalable and inexpensive method the researchers produced hybrid electrodes the building blocks of touchscreen technology from silver nanowires and graphene.
Lead author Dr Izabela Jurewicz from the University of Surrey commented Our work has cut the amount of expensive nanowires required to build such touchscreens by more than fifty times as well as simplifying the production process.
Conductive nanofiber networks for flexible unbreakable and transparent electrode e
#Harnessing an unusual'valley'quantum property of electrons Yoshihiro Iwasa and colleagues from the RIKEN Center for Emergent Matter Science the University of Tokyo and Hiroshima University have discovered that ultrathin films of a semiconducting material have properties that form the basis for a new kind of low-power electronics
In the form of nanowires and nanoparticles it has particular potential for use in the manufacture of solar cells
It had already been demonstrated on nanowires made from one crystalline form of gallium arsenide the cubic so-called zincblende structure that the band gap widens under pressure.
The present research focused instead on nanowires of a less-common crystalline form the hexagonal so-called wurtzite structure.
They discovered the band gap that the electrons need to leap across to also widened although not as much as in the case of the zincblende crystal nanowires.
Significantly they discovered that around 207000 times normal atmospheric pressure (21 gigapascals) the wurtzite gallium arsenide nanowires underwent a structural change that induced a new phase the so-called orthorhombic one
or even a single nanowire and realize much more complex and useful electronic functions through interactions across the phases Goncharov said.
#Controlling photoluminescence with silicon nanophotonics for better devices Silicon nanowires have a great deal of potential in future high-performance electronic sensing and energy devices.
Red photoluminescence has been reported in silicon nanowires but for many applications this hampers device performance. As Tsuyoshi Okuno from the University of Electro-Communications and his colleagues point out in a recent report
Okuno and his colleagues fabricated silicon nanowire arrays by metal-assisted chemical etching an approach that is simple and cost-effective.
and etched nanowires using aqueous H2o2. Although the researchers did not have precise control over the nanowire morphology they did observe that higher concentrations of H2o2 led to thicker nanowires.
Photoluminescence studies did not reveal a link between photoluminescence and nanowire diameter or length alone but low aspect ratio nanowires exhibited red photoluminescence.
Further observations of the morphology identified silicon nanocrystals at the nanowire ends which was corroborated by Raman studies of single nanowires.
These nanocrystals disappear on annealing as does the red photoluminescence. The researchers attribute the red photoluminescence to defect states between nanocrystals and surrounding oxide and excitonic transitions.
As the researchers conclude in their report These results of Si nanowire arrays are believed to be useful for future optoelectronic and photovoltaic applications.
Oda K. Nanai Y. Sato T. Kimura S. & Okuno T. Correlation between photoluminescence and structure in silicon nanowires fabricated by metal-assisted etching.
or'top-down'methods widely used for the fabrication of nanostructures. Notably electrons in quantum dot structures are confined inside nanometer sized three dimension boxes.
#Fabrication route improves the properties of aluminum-based nanocomposites One challenge in producing strong elastic
and hard-wearing nanocomposites is obtaining an even distribution of the nanoparticles in the metal matrix.
Their technique is a viable new method for manufacturing nanocomposites and has exciting potential for the car space and defense industries.
The team used scanning electron microscopy to check two key properties that influence the strength of nanocomposites.
We plan to continue this research to further improve the mechanical and thermal properties as well as the wear resistance of the nanocomposites says Guo.
#Researchers uncover properties in nanocomposite oxide ceramics for reactor fuel Nanocomposite oxide ceramics have potential uses as ferroelectrics fast ion conductors
In a nanocomposite the size of each of these grains is on the order of nanometers roughly 1000 times smaller than the width of a human hair.
and radiation damage resistance of oxide nanocomposites by controlling the termination chemistry at the interface.
We believe that this discovery that the interface structure is sensitive to the chemistry of the interface will open the door for new research directions in oxide nanocomposites said Blas Uberuaga lead researcher on the effort.
Gan microstructures and nanostructures are garnering attention within the research community as light-emitting devices because of their variable-color light emission
#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:
and gold nanowires approx. 12 nanometres in diameter and 42 nanometres in length. The gold wire is therefore only about one ten-thousandth the thickness of a hair.
The microsphere and nanowire amplify the interaction between light and molecules. With the help of a prism, the researchers shine laser light into the microsphere.
Vollmer and his colleagues therefore fix a nanowire to the surface of the glass bead.
to the nanowire mounted on the microsphere. When a matching, i e. COMPLEMENTARY DNA fragment binds to the"bait"on the nanowire
the wavelength of the light shifts and is amplified by the microsphere and nanowire. This shift can be measured.
Different strand sections can be distinguished by their binding behaviour However, the physicists used a shorter DNA fragment than is usual in similar procedures.
#Nanoribbon film keeps glass ice-free: Team refines deicing film that allows radio frequencies to pass Rice university scientists who created a deicing film for radar domes have refined now the technology to work as a transparent coating for glass.
The material is made of graphene nanoribbons atom-thick strips of carbon created by splitting nanotubes a process also invented by the Tour lab
Last year the Rice group created films of overlapping nanoribbons and polyurethane paint to melt ice on sensitive military radar domes
In the previous process the nanoribbons were mixed with polyurethane but testing showed the graphene nanoribbons themselves formed an active network when applied directly to a surface.
He said nanoribbon films also open a path toward embedding electronic circuits in glass that are both optically and RF transparent a
#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.
It is expected highly that the N-ACNT/G sandwiches hold various potential applications in the area of nanocomposite energy storage environmental protection electronic device as well as healthcare because of their robust hierarchical structure 3d electron transfer
and fabrication strategy is generally applicable we foresee a new branch of material chemistry evolving in the area of advanced hierarchical nanostructures through the 3d topological nanosystems and interfacial modification.
Tang C Zhang Q Zhao MQ Huang JQ Cheng XB Tian GL Peng HJ Wei F. Nitrogen-Doped Aligned Carbon nanotube
and then use those nanostructures like LEGO to construct larger materials, you can obtain nearly any set of properties you want.
what they call three-dimensional nanolattices that are formed by a repeating nanoscale pattern. After the patterning step,
and undoped graphene pieces they were able to form heterojunctions in the nanoribbons thereby fulfilling a basic requirement for electronic current to flow in only one direction
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,
either by patterning graphene to make nanoribbons or by introducing defects in the graphene layerr using bilayer graphene stacked in a certain pattern that allows band gap opening upon application of a vertical electric fieldor better control and detection of current.
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.
At present the scientific community worldwide is actively seeking practical applications of 2d semiconductor materials such as Mos2 nanosheets.
and Swiss Federal Institute of technology in Zurich describe a basic model circuit consisting of a silver nanowire and a single-layer flake of molybendum disulfide (Mos2).
K. Goodfellow R. Beams C. Chakraborty L. Novotny A n. Vamivakas Integrated nanophotonics based on nanowire plasmons and atomically-thin material Optica Vol. 1 Issue
Along with colleagues at the University of Manchester researchers captured the world's first real-time images and simultaneous chemical analysis of nanostructures while underwater or in solution.
This lets scientists watch as nanostructures grow and change with time during chemical reactions. The team is now working with the manufacturer Protochips Inc. to make this capability available to the scientific community.
The study Real-time imaging and local elemental analysis of nanostructures in liquids was published in the journal Chemical Communications with researchers from the University of Manchester and BP.
Real-time imaging and local elemental analysis of nanostructures in liquids. Edward A. Lewis et al. Chem.
#Conductive nanofiber networks for flexible unbreakable and transparent electrodes Transparent conductors are required as electrodes in optoelectronic devices, such as touch panel screens, liquid crystal displays, and solar cells.
Tokyo Institute of technology researchers report the first development of a facile method for the fabrication of flexible and unbreakable transparent electrodes using nanofibers.
Two-dimensional aluminum (Al) nanofiber networks offering transparent conductors were fabricated by simple wet chemical etching of Al metalized polymer films using an electrospun polystyrene nanofiber mask template.
The resulting Al nanowire networksith a width of 500 nm and an area fraction of 22.0%xhibited 80%optical transmittance and sheet resistance of 45 O sq-1
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.
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.
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.
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011