#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 new work by Rice chemist James Tour and his colleagues could keep glass surfaces from windshields to skyscrapers free of ice
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
The graphene-infused paint worked well Tour said but where it was thickest it would break down
The new films are between 50 and 200 nanometers thick a human hair is about 50000 nanometers thick
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.
They were coated subsequently with a thin layer of polyurethane for protection. Samples were spread onto glass slides that were iced then.
He said nanoribbon films also open a path toward embedding electronic circuits in glass that are both optically and RF transparent a
#The future face of molecular electronics The emerging field of molecular electronics could take our definition of portable to the next level enabling the construction of tiny circuits from molecular components.
Picene's sister molecule pentacene has been studied widely because of its high carrier mobilityts ability to quickly transmit electrons a critical property for nanoscale electronics.
The weak interaction is advantageous for molecular electronics applications because the modification of the properties of molecular thin film by the presence of the silver is negligible
For this study scientists looked at a positive electrode made of billions of nanoparticles of lithium iron phosphate.
Previous studies produced conflicting views of how the nanoparticles behaved. To probe further researchers made small coin cell batteries charged them with different levels of current for various periods of time quickly took them apart
We were able to look at thousands of electrode nanoparticles at a time and get snapshots of them at different stages during charging
Analyzing the data using a sophisticated model developed at MIT the researchers discovered that only a small percentage of nanoparticles absorbed and released ions during charging even
#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
and graphene were grown on the NPS and lamellar flakes at L -and H-T CVD respectively and conjointly. first-author Cheng Tang explained to Phys.
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.
The 3d interconnected mesoporous space improves the penetration and diffusion of electrolytes. Additionally the nitrogen-modified interfaces give rise to enhanced interfacial affinity for efficient confinement and utilization of sulfur and polysulfides.
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.
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
/Graphene Sandwiches: Facile Catalytic Growth on Bifunctional Natural Catalysts and Their Applications as Scaffolds for High-Rate Lithium-Sulfur Batteries.
Greer's team has developed a method for constructing new structural materials by taking advantage of the unusual properties that solids can have at the nanometer scale,
if you use the concept of the nanoscale to create structures and then use those nanostructures like LEGO to construct larger materials,
you can obtain nearly any set of properties you want. You can create materials by design."
what they call three-dimensional nanolattices that are formed by a repeating nanoscale pattern. After the patterning step,
aluminum oxide), producing hollow-tube alumina structures with walls ranging in thickness from 5 to 60 nanometers and tubes from 450 to 1, 380 nanometers in diameter.
and prodding materials on the nanoscale, they squished, stretched, and otherwise tried to deform the samples to see how they held up.
They found that the alumina structures with a wall thickness of 50 nanometers and a tube diameter of about 1 micron shattered when compressed.
when you reduce these structures down to the point where individual walls are only 10 nanometers thick,
#'Human touch'nanoparticle sensor could improve breast cancer detection (Phys. org) niversity of Nebraska-Lincoln scientists have developed a nanoparticle-based device that emulates human touch
In research funded with a grant from the National institutes of health, Saraf and Nguyen perfected a thin film made of nanoparticles and polymers
#Team uses nanotechnology to help cool electrons with no external sources A team of researchers has discovered a way to cool electrons to#228°C without external means and at room temperature,
The team used a nanoscale structure which consists of a sequential array of a source electrode, a quantum well,
a tunneling barrier, a quantum dot, another tunneling barrier, and a drain electrode to suppress electron excitation
#Molecular self-assembly controls graphene-edge configuration A research team headed by Prof. Patrick Han and Prof.
Taro Hitosugi at the Advanced Institute of Materials Research (AIMR), Tohoku University discovered a new bottom-up fabrication method that produces defect-free graphene nanoribbons (GNRS) with periodic zigzag-edge regions.
and length distribution, is a stepping stone towards future graphene device fabrication by self-assembly. Graphene, with its low dimensionality, high stability, high strength,
and high charge-carrier mobility, promises to be a revolutionary material for making next-generation high-speed transistors.
graphene's properties are predicted to be directly controllable by its structure. For example, recent works have demonstrated that the bandgap of armchair GNRS is controlled by the ribbon width.
These features could be exploited for making single graphene interconnections between prefabricated structures by self-assembly."
"Our method opens the possibility for self-assembling single graphene devices at desired locations, because of the length and of the direction control. t
#Engineers advance understanding of graphene's friction properties (Phys. org) An interdisciplinary team of engineers from the University of Pennsylvania has made a discovery regarding the surface properties of graphene the Nobel-prize winning material that consists of an atomically thin sheet
However on the nanoscale adding fluorine to graphene had been reported to vastly increase the friction experienced
Besides its applications in circuitry and sensors graphene is of interest as a super-strong coating.
Because graphene is so strong thin and smooth one of its potential applications is to reduce friction and increase the lifespan of these devices.
We wanted to better understand the fundamental mechanisms of how the addition of other atoms influences the friction of graphene.
The addition of fluorine atoms to graphene's carbon lattice makes for an intriguing combination
so we thought fluorinated graphene might be like two-dimensional Teflon. To test the friction properties of this material the Penn researchers collaborated with Paul Sheehan and Jeremy Robinson of the Naval Research Laboratory.
Sheehan and Robinson were the first to discover fluorinated graphene and are experts in producing samples of the material to specification.
This meant we were able to systematically vary the degree of fluorination in our graphene samples
when we tested the friction of these different samples with an atomic force microscope an ultra-sensitive instrument that can measure nanonewton forces.
The researchers were surprised to find that adding fluorine to graphene increased the material's friction
they also showed that the addition of fluorine increased the stiffness of the graphene samples and hypothesized this was increased responsible for the friction.
whose expertise is in developing atomic scale simulations of mechanical action to help explain what the addition of the fluorine was doing to the graphene's surface.
It turns out that by adding fluorine Liu said we're changing the energy corrugation landscape of the graphene.
which at the nanoscale can act like physical roughness in increasing friction. In fluorinated graphene the fluorine atoms do stick up out of the plane of carbon atoms
but the physical changes in height paled in comparison to the changes of local energy each fluorine atom produced.
At the nanoscale Carpick said friction isn't just determined by the placement of atoms
and deep valleys in between them compared to the smooth plane of regular graphene. You could say it's like trying slide over a smooth road versus a bumpy road.
Beyond the implication for graphene's coating applications the team's findings provide fundamental insight into graphene's surface properties.
Seeing that fluorine increases friction in graphene isn't necessarily a bad thing since it may give us a way to tailor that property to a given application.
On the edge of graphene More information: Fluorination of Graphene Enhances Friction Due to Increased Corrugation.
Qunyang Li Xin-Z. Liu Sang-Pil Kim Vivek B. Shenoy Paul E. Sheehan Jeremy T. Robinson and Robert W. Carpick.
#Doped graphene nanoribbons with potential Graphene is a semiconductor when prepared as an ultra-narrow ribbon although the material is actually a conductive material.
Researchers from Empa and the Max Planck Institute for Polymer Research have developed now a new method to selectively dope graphene molecules with nitrogen atoms.
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
when voltage is applied the first step towards a graphene transistor. Furthermore the team has managed successfully to remove graphene nanoribbons from the gold substrate on
which they were grown and to transfer them onto a nonconductive material. Graphene possesses many outstanding properties it conducts heat
and electricity it is transparent harder than diamond and extremely strong. But in order to use it to construct electronic switches a material must not only be an outstanding conductor it should also be switchable between on and off states.
The problem however is that the bandgap in graphene is extremely small. Empa researchers from the nanotech@surfaces laboratory thus developed a method some time ago to synthesise a form of graphene with larger bandgaps by allowing ultra-narrow graphene nanoribbons to grow via molecular self-assembly.
Graphene nanoribbons made of differently doped segmentsthe researchers led by Roman Fasel have achieved now a new milestone by allowing graphene nanoribbons consisting of differently doped subsegments to grow.
Instead of always using the same pure carbon molecules they used additionally doped molecules molecules provided with foreign atoms in precisely defined positions in this case nitrogen.
The researchers describe the corresponding heterojunctions in segmented graphene nanoribbons in the recently published issue of Nature Nanotechnology.
Transferring graphene nanoribbons onto other substratesin addition the scientists have solved another key issue for the integration of graphene nanotechnology into conventional semiconductor industry:
how to transfer the ultra-narrow graphene ribbons onto another surface? As long as the graphene nanoribbons remain on a metal substrate (such as gold used here) they cannot be used as electronic switches.
Gold conducts and thus creates a short-circuit that sabotages the appealing semiconducting properties of the graphene ribbon.
Fasel's team and colleagues at the Max-Planck-Institute for Polymer Research in Mainz have succeeded in showing that graphene nanoribbons can be transferred efficiently
and intact using a relatively simple etching and cleaning process onto (virtually) any substrate for example onto sapphire calcium fluoride or silicon oxide.
Graphene is thus increasingly emerging as an interesting semiconductor material and a welcome addition to the omnipresent silicon.
The semiconducting graphene nanoribbons are particularly attractive as they allow smaller and thus more energy efficient and faster electronic components than silicon.
However the generalized use of graphene nanoribbons in the electronics sector is anticipated not in the near future due in part to scaling issues
Fasel estimates that it may still take about 10 to 15 years before the first electronic switch made of graphene nanoribbons can be used in a product.
Graphene nanoribbons for photovoltaic componentsphotovoltaic components could also one day be based on graphene. In a second paper published in Nature Communications Pascal Ruffieux also from the Empa nanotech@surfaces laboratory
and his colleagues describe a possible use of graphene strips for instance in solar cells. Ruffieux and his team have noticed that particularly narrow graphene nanoribbons absorb visible light exceptionally well
and are therefore highly suitable for use as the absorber layer in organic solar cells. Compared to normal graphene
which absorbs light equally at all wavelengths the light absorption in graphene nanoribbons can be increased enormously in a controlled way
whereby researchers set the width of the graphene nanoribbons with atomic precision n
#Rethinking basic science of graphene synthesis shows route to industrial-scale production A new route to making graphene has been discovered that could make the 21st century's wonder material easier to ramp up to industrial scale.
Graphene tightly bound single layer of carbon atoms with super strength and the ability to conduct heat
and electricity better than any other known materialas potential industrial uses that include flexible electronic displays, high-speed computing, stronger wind turbine blades,
and more-efficient solar cells, to name just a few under development. In the decade since Nobel laureates Konstantin Novoselov and Andre Geim proved the remarkable electronic and mechanical properties of graphene
researchers have been hard at work to develop methods of producing pristine samples of the material on a scale with industrial potential.
Now, a team of Penn State scientists has discovered a route to making single-layer graphene that has been overlooked for more than 150 years."
"There are lots of layered materials similar to graphene with interesting properties, but until now we didn't know how to chemically pull the solids apart to make single sheets without damaging the layers,
"said Thomas E. Mallouk, Evan Pugh Professor of Chemistry, Physics, and Biochemistry and Molecular biology at Penn State.
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,
and graphene could apply to many other layered materials of interest to researchers in the Penn State Center for Two-dimensional and Layered Materials who are investigating
what are referred to as"Materials Beyond Graphene.""The next step for Mallouk and colleagues will be to figure out how to speed the reaction up
Using the special properties of graphene a two-dimensional form of carbon that is only one atom thick a prototype detector is able to see an extraordinarily broad band of wavelengths.
A research paper about the new detector was published Sunday September 07 2014 in Nature Nanotechnology.
and colleagues at the U s. Naval Research Lab and Monash University Australia gets around these problems by using graphene a single layer of interconnected carbon atoms.
By utilizing the special properties of graphene the research team has been able to increase the speed
Graphene a sheet of pure carbon only one atom thick is suited uniquely to use in a terahertz detector
because when light is absorbed by the electrons suspended in the honeycomb lattice of the graphene they do not lose their heat to the lattice
Light is absorbed by the electrons in graphene which heat up but don't lose their energy easily.
These heated electrons escape the graphene through electrical leads much like steam escaping a tea kettle.
Sensitive Room-temperature Terahertz Detection via Photothermoelectric Effect in Graphene Xinghan Cai et al. Nature Nanotechnology dx. doi. org/10.1038/nnano. 2014.18
#First graphene-based flexible display produced A flexible display incorporating graphene in its pixels'electronics has been demonstrated successfully by the Cambridge Graphene Centre and Plastic Logic,
the first time graphene has been used in a transistor-based flexible device. The partnership between the two organisations combines the graphene expertise of the Cambridge Graphene Centre (CGC),
with the transistor and display processing steps that Plastic Logic has developed already for flexible electronics.
This prototype is a first example of how the partnership will accelerate the commercial development of graphene,
and is a first step towards the wider implementation of graphene and graphene-like materials into flexible electronics.
Graphene is a two-dimensional material made up of sheets of carbon atoms. It is among the strongest most lightweight and flexible materials known,
and has the potential to revolutionise industries from healthcare to electronics. The new prototype is an active matrix electrophoretic display,
or backplane, of this display includes a solution-processed graphene electrode, which replaces the sputtered metal electrode layer within Plastic Logic's conventional devices,
Graphene is more flexible than conventional ceramic alternatives like indium-tin oxide (ITO) and more transparent than metal films.
The ultra-flexible graphene layer may enable a wide range of products including foldable electronics. Graphene can also be processed from solution bringing inherent benefits of using more efficient printed
and roll-to-roll manufacturing approaches. The new 150 pixel per inch (150 ppi) backplane was made at low temperatures (less than 100°C) using Plastic Logic's Organic Thin Film Transistor (OTFT) technology.
The graphene electrode was deposited from solution and subsequently patterned with micron-scale features to complete the backplane.
"We are happy to see our collaboration with Plastic Logic resulting in the first graphene-based electrophoretic display exploiting graphene in its pixels'electronics,
"said Professor Andrea Ferrari, Director of the Cambridge Graphene Centre.""This is a significant step forward to enable fully wearable and flexible devices.
This cements the Cambridge graphene technology cluster and shows how an effective academic-industrial partnership is key to help move graphene from the lab to the factory floor.""
""The potential of graphene is well-known, but industrial process engineering is required now to transition graphene from laboratories to industry,
"said Indro Mukerjee, CEO of Plastic Logic.""This demonstration puts Plastic Logic at the forefront of this development,
which will soon enable a new generation of ultra-flexible and even foldable electronics"This joint effort between Plastic Logic
within the'realising the graphene revolution'initiative. This will target the realisation of an advanced, full colour, OELD based display within the next 12 months h
#Team develops ultra sensitive biosensor from molybdenite semiconductor Move over graphene. An atomically thin two-dimensional ultrasensitive semiconductor material for biosensing developed by researchers at UC Santa barbara promises to push the boundaries of biosensing technology in many fields from health care to environmental protection to forensic industries.
Based on molybdenum disulfide or molybdenite (Mos2) the biosensor materialsed commonly as a dry lubricanturpasses graphene's already high sensitivity offers better scalability
While graphene has attracted wide interest as a biosensor due to its two-dimensional nature that allows excellent electrostatic control of the transistor channel by the gate
and high surface-to-volume ratio the sensitivity of a graphene field-effect transistor (FET) biosensor is restricted fundamentally by the zero band gap of graphene that results in increased leakage current leading to reduced sensitivity
explained Banerjee who is also the director of the Nanoelectronics Research Lab at UCSB. Graphene has been used among other things to design FETSEVICES that regulate the flow of electrons through a channel via a vertical electric field directed into the channel by a terminal called a gate.
In digital electronics these transistors control the flow of electricity throughout an integrated circuit and allow for amplification and switching.
Graphene has received wide interest in the biosensing field and has been used to line the channel and act as a sensing element
despite graphene's excellent characteristics its performance is limited by its zero band gap. Electrons travel freely across a graphene FETENCE it cannot be switched offhich in this case results in current leakages and higher potential for inaccuracies.
Much research in the graphene community has been devoted to compensating for this deficiency 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.
Enter Mos2 a material already making waves in the semiconductor world for the similarities it shares with graphene including its atomically thin hexagonal structure and planar nature as well as
what it can do that graphene can't: act like a semiconductor. Monolayer or few-layer Mos2 have a key advantage over graphene for designing an FET biosensor:
They have a relatively large and uniform band gap (1. 2-1. 8 ev depending on the number of layers) that significantly reduces the leakage current
and increases the abruptness of the turn-on behavior of the FETS thereby increasing the sensitivity of the biosensor said Banerjee.
Additionally according to Deblina Sarkar a Phd student in Banerjee's lab and the lead author of the article two-dimensional Mos2 is relatively simple to manufacture.
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.
Professor Banerjee and his team have identified a breakthrough application of these nanomaterials and provided new impetus for the development of low-power
New rapid synthesis developed for bilayer graphene and high-performance transistors More information: ACS Nano pubs. acs. org/doi/abs/10.1021/nn500914 i
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).
We have found that there is pronounced nanoscale light-matter interaction between plasmons and atomically thin material that can be exploited for nanophotonic integrated circuits said Nick Vamivakas assistant professor of quantum optics and quantum physics at the University of Rochester and senior author of the paper.
Ever since the discovery of graphene a single layer of carbon that can be extracted from graphite with adhesive tape scientists have been rapidly exploring the world of two-dimensional materials These materials have unique properties not seen in their bulk form.
Like graphene Mos2 is made up of layers that are bonded weakly to each other so they can be separated easily.
Graphene is inefficient at light emission because it has no band gap. Combining electronics and photonics on the same integrated circuits could drastically improve the performance and efficiency of mobile technology.
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
#Researcher's nanoparticle key to new malaria vaccine A self-assembling nanoparticle designed by a UCONN professor is the key component of a potent new malaria vaccine that is showing promise in early tests.
But a novel protein nanoparticle developed by Peter Burkhard, a professor in the Department of Molecular & Cell biology, in collaboration with David Lanar
The key to the vaccine's success lies in the nanoparticle's perfect icosahedral symmetry (think of the pattern on a soccer ball)
We are able to achieve our high density because of the design of the nanoparticle, which we control."
It took the researchers more than 10 years to finalize the precise assembly of the nanoparticle as the critical carrier of the vaccine
holds the patent on the self-assembling nanoparticle used in the malaria vaccine. Burkhard is also exploring other potential uses for the nanoparticle,
including a vaccine that will fight animal flu and one that will help people with nicotine addiction.
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