a laboratory usually devoted to studying fuel cellshe kind that run on methane or hydrogened by Shriram Ramanathan, Associate professor of Materials science at the Harvard School of engineering and Applied sciences (SEAS.
Doping is the process of introducing different atoms into the crystal structure of a material, and it affects how easily electrons can move through ithat is,
"The occupancy of the orbitals and the ability of electrons to move in the crystal are tied very closely togetherr'correlated.'
'Fundamentally, that's what dictates whether the material behaves as an insulator or a metal."
To test picene's properties when juxtaposed with a metal as it would be in an electronic device the researchers deposited a single layer of picene molecules onto a piece of silver.
but it's one that until this study was understood not adequately said William Chueh of SIMES an assistant professor at Stanford's Department of Materials science and engineering and senior author of the study.
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
and thermal conductivity but also on their tunable chemical characters such as functional groups doping and surface modification.
The combination of CNTS and graphene into 3d hybrid composites can usually mitigate the self-aggregation
Rational hybridization of N-doped graphene/carbon nanotubes for oxygen reduction and oxygen evolution reaction More information:
#Ceramics don't have to be brittle: Materials scientists are creating materials by design Imagine a balloon that could float without using any lighter-than-air gas.
the Caltech researchers explain how they used the method to produce a ceramic (e g.,, a piece of chalk or a brick) that contains about 99.9 percent air yet is incredibly strong
"Ceramics have always been thought to be heavy and brittle, "says Greer, a professor of materials science and mechanics in the Division of Engineering and Applied science at Caltech."
"We're showing that in fact, they don't have to be either. This very clearly demonstrates that
"The researchers use a direct laser writing method called two-photon lithography to"write"a three-dimensional pattern in a polymer by allowing a laser beam to crosslink
and harden the polymer wherever it is focused. The parts of the polymer that were exposed to the laser remain intact
while the rest is dissolved away, revealing a three-dimensional scaffold. That structure can then be coated with a thin layer of just about any kind of material metal, an alloy, a glass, a semiconductor, etc.
Then the researchers use another method to etch out the polymer from within the structure
leaving a hollow architecture. The applications of this technique are practically limitless, Greer says. Since pretty much any material can be deposited on the scaffolds,
they coated the polymer scaffold with a ceramic called alumina (i e.,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.
That was not surprising given that ceramics especially those that are porous, are brittle. However, compressing lattices with a lower ratio of wall thickness to tube diameterhere the wall thickness was only 10 nanometersroduced a very different result."
"To understand why, consider that most brittle materials such as ceramics, silicon, and glass shatter because they are filled with flawsmperfections such as small voids and inclusions.
In research funded with a grant from the National institutes of health, Saraf and Nguyen perfected a thin film made of nanoparticles and polymers
Using a silicone breast model identical to those used to train doctors in manual breast exams,
"said Seong Jin Koh, an associate professor at UT Arlington in the Materials science & Engineering Department,
They collaborated with Vivek Shenoy a professor in the Department of Materials science and engineering. The Penn contingent also worked with researchers from the Naval Research Laboratory and Brown University.
Teflon is fluorinated a carbon polymer so we thought fluorinated graphene might be like two-dimensional Teflon.
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 negative charges across different regions of the semiconductor crystal thereby creating the basic structure allowing the development of many components used in the semiconductor industry.
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
to open up single layers of solid boron nitride, a compound with a structure similar to graphite.
"Mallouk believes the results of this new understanding of intercalation in boron nitride 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
The light in these terahertz wavelengths can pass through materials that we normally think of as opaque such as skin plastics clothing and cardboard.
The prototype uses two electrical leads made of different metals which conduct electrons at different rates.
with the transistor and display processing steps that Plastic Logic has developed already for flexible electronics.
except it is made of flexible plastic instead of Glass in contrast to conventional displays, the pixel electronics,
Graphene is more flexible than conventional ceramic alternatives like indium-tin oxide (ITO) and more transparent than metal films.
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.
"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
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.
an expert in structural biology affiliated with UCONN's Institute of Materials science.""With RTS, S, only about 14 percent of the vaccine's protein is from the malaria parasite.
Guiding Brain tumor Resection Using Surface-Enhanced Raman Scattering Nanoparticles and a Hand-held Raman Scanner ACS Nano Article ASAPDOI:
because it uses inert gold#silica SERS nanoparticles and a hand-held Raman scanner that can guide brain tumor resection in the operating room o
but immensely powerful batteries) and an array of new materials that could make many of today's common metals and polymers redundant.
"said senior author Xiaodong Xu, a UW assistant professor of materials science and engineering and of physics.""Our experimental demonstration of such junctions between two-dimensional materials should enable new kinds of transistors, LEDS, nanolasers,
which was key to creating the composite two-dimensional semiconductor. Collaborators from the electron microscopy center at the University of Warwick in England found that all the atoms in both materials formed a single honeycomb lattice structure, without any distortions or discontinuities.
and deposited as single-layer crystals in the shape of triangles. After a while, evaporated atoms from the second material then attached to the edges of the triangle to create a seamless semiconducting heterojunction."
On a small scale, it takes about five minutes to grow the crystals, with up to two hours of heating and cooling time."
efficient charge transfer in MX2 heterostructures through combined photoluminescence mapping and transient absorption measurements,"says Feng Wang, a condensed matter physicist with Berkeley Lab's Materials sciences Division
MX2 monolayers consist of a single layer of transition metal atoms, such as molybdenum (Mo) or tungsten (W), sandwiched between two layers of chalcogen atoms,
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
and could be embedded further into polymeric elastomers extremely flexible, stretchable materials to obtain conducting rubbers."
In contrast to other dichroic effects produced by some crystals, such as precious opals, the colorful effects of the Lycurgus cup have little dependence on the position of the observer.
In fact, the dichroism found in the Lycurgus cup has a different origin than crystals and so far this'plasmonic effect'has not been observed in naturally occurring materials."
is produced by plasmonic-enhanced optical scattering of the nanostructures. The subwavelength distance offers certain advantages.
#Eco-friendly'prefab nanoparticles'could revolutionize nano manufacturing A team of materials chemists polymer scientists device physicists
Lahti likens the UMASS Amherst team's advance in materials science to the kind of benefits the construction industry saw with prefabricated building units.
For photovoltaics Venkataraman points out The next thing is to make devices with other polymers coming along to increase power conversion efficiency
The'seeds'are multiple crystals of elongated gold decahedrons, joined together by shared facesn arrangement known as multiply-twinning.
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."
Last year, Dr Joe Briscoe and Dr Steve Dunn from QMUL's School of engineering and Materials science found that playing pop
The team used the key properties of zinc oxide, a material that when squashed or stretched creates a voltage by converting energy from motion into electrical energy, in the form of nanorods.
whereby they could spray on the nanorod chemicals almost like nanorod graffiti to cover a plastic sheet in a layer of zinc oxide.
Under the guidance of Canada Research Chair in Materials science with Synchrotron radiation Dr. Alexander Moewes University of Saskatchewan researcher Adrian Hunt spent his Phd investigating graphene oxide a cutting-edge material that he hopes will shape the future
and it's extremely strong its tensile strength is even stronger than steel Hunt said. Air doesn't damage it.
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:
or a few atomic layers are currently a hot topic in materials science today. Research on two-dimensional materials started with graphene,
"Quite often, two-dimensional crystals have electronic properties that are completely different from those of thicker layers of the same material,
But a solar cell made only of tungsten diselenide would require countless tiny metal electrodes tightly spaced only a few micrometers apart.
graphene is a 2d sheet of carbon just one atom Thick with a'honeycomb'structure the'wonder material'is 100 times stronger than steel, highly conductive and flexible.
Under certain PH conditions they found that graphene behaves like a polymer-changing shape by itself.
made of silica and nickel, is only 70 nm in diameter; the entire propeller is 400 nm long.
The hyaluronan gel contains a mesh of long proteins called polymers; the polymers are large enough to prevent micrometer-sized propellers from moving much at all.
But the openings are large enough for nanometer-sized objects to pass through. The scientists were able to control the motion of the propellers using a relatively weak rotating magnetic field.
#Existence of two-dimensional nanomaterial silicene questioned Sometimes scientific findings can shake the foundations of what was held once to be true causing us to step back
A recent study at the U s. Department of energy's Argonne National Laboratory has called into question the existence of silicene thought to be one of the world's newest and hottest two-dimensional nanomaterials.
Silicene was proposed as a two-dimensional sheet of silicon atoms that can be created experimentally by super-heating silicon
Both silicene and silicon should react immediately with oxygen but they react slightly differently. In the case of silicon oxygen breaks some of the silicon bonds of the first one
Because it consists of only one layer of silicon atoms silicene must be handled in a vacuum.
After depositing the atoms onto the silver platform initial tests identified that alloy-like surface phases would form until bulk silicon layers
which has been mistaken as two-dimensional silicene. Some of the bulk silicon platelets were more than one layer thick said Argonne scientist Nathan Guisinger of Argonne's Center for Nanoscale Materials.
Each new series of experiments presented a new set of clues that this was in fact not silicene.
We found out that what previous researchers identified as silicene is really just a combination of the silicon
Their sample did not exhibit characteristic vibrations of silicene but it did match those of silicon.
if you are trying to grow silicene. Explore further: Wonder material silicene has suicidal tendencie e
#Discovery is key to metal wear in sliding parts (w/Video) Researchers have discovered a previously unknown mechanism for wear in metals:
a swirling, fluid-like microscopic behavior in a solid piece of metal sliding over another.
The findings could be used to improve the durability of metal parts in numerous applications.""Wear is a major cause of failure in engineering applications,
"Using high-resolution imaging of sliding contacts in metals, we have demonstrated a new way by which wear particles and surface defects can form,
and the sliding conditions did not generate enough heat to soften the metal. Yet, the swirling flow is more like behavior seen in fluids than in solids,
The team observed what happens when a wedge-shaped piece of steel slides over a flat piece of aluminum or copper.
The metals are used commonly to model the mechanical behavior of metals.""We speculated in the earlier paper that the swirly fluid-like surface flow discovered on sliding metal surfaces is likely to impact wear in sliding metal systems,
"he said.""Now we are confirming this speculation by direct observations
#Graphene and related materials promise cheap flexible printed cameras Dr Felice Torrisi University Lecturer in Graphene technology has been awarded a Young International Researchers'Fellowship from the National Science Foundation
or stamped on plastic or paper. For example it might eventually be embed possible to these printed flexible optoelectronic devices into clothes packaging wall papers posters touch screens or even buildings.
and characterize inkjet printed 2d crystal-based flexible photodetectors and study their integration with commercial electronics.
The current generation of flexible photoactive materials based on organic polymers have a slow response time (few milliseconds)
Moreover organic polymers suffer from chemical instability at room conditions temperature and pressure) thus requiring extra protective layers
Graphene the ultimate thin membrane along with a wide range of two-dimensional (2d)- crystals (e g. hexagonal Boron nitride (h-BN) Molybdenum Disulfide (Mos2) and Tungsten Disulfide (WS2)) have changed radically the landscape
These 2d crystals can be exfoliated from layered compounds. The layered compounds can be conductive semiconducting
and it is superior to conductive polymers in terms of cost stability and performance; whereas Mos2 is optically active once reduced to a single 2d layer with a fast response time and excellent environmental stability.
Other conductive inks are made from precious metals such as silver which makes them very expensive to produce
and the team at the Cambridge Graphene Centre have been looking to formulate a set of inks based on various 2d crystals setting a new platform for printed electronics.
When light impinges on a semiconducting 2d crystal (e g. Mos2) due to their 2d nature electrons and holes are generated with a higher efficiency than the current photodetectors based on siliconthe project funded by the National Natural science Foundation of China looks into how to design printed flexible photodetectors
#A crystal wedding in the nanocosmos Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), the Vienna University of Technology and the Maria Curie-Sklodowska University Lublin have succeeded in embedding nearly perfect semiconductor crystals
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,
ion beam synthesis and heat treatment with xenon flash-lamps were used, two technologies in which the Ion beam Center of the HZDR has held experience for many years.
"while the implanted atoms form the indium arsenide crystals.""Dr. Wolfgang Skorupa, the head of the research group adds:"
"The atoms diffuse in the liquid-silicon-phase so rapidly that within milliseconds they form flawless mono-crystals delineated from their surroundings with nearly perfect interfaces."
and also optimize the size and distribution of the crystals a
#Tiny laser sensor heightens bomb detection sensitivity New technology under development at the University of California,
who is also director of the Materials science Division at the Lawrence Berkeley National Laboratory and director of the National Science Foundation Nanoscale Science and Engineering Center at UC Berkeley."
the oscillating electrons found at the surface of metals, researchers were able to squeeze light into nanosized spaces,
because light tends to dissipate at a metal's surface. The new device builds upon earlier work in plasmon lasers by Zhang's lab that compensated for this light leakage by using reflectors to bounce the surface plasmons back and forth inside the sensor similar to the way sound waves are reflected across the room
Fortunately researchers have pinpointed now the breaking mechanism of several monolayer materials hundreds of times stronger than steel with exotic properties that could revolutionize everything from armor to electronics.
The team virtually examined this exotic phase transition in graphene boron nitride molybdenum disulfide and graphane all promising monolayer materials.
of which can be compared directly to experimental data said Chris Marianetti a professor of materials science at Columbia University and coauthor of the study.
and whether they acted as metals semiconductors or insulators under strain. Toggling between or sustaining those conductive properties are particularly important for future applications in microelectronics.
Within the honeycomb-like lattices of monolayers like graphene boron nitride and graphane the atoms rapidly vibrate in place.
In the case of graphene boron nitride and graphane the backbone of the perfect crystalline lattice distorted toward isolated hexagonal rings.
The soft mode distortion ended up breaking graphene boron nitride and molybdenum disulfide. As the monolayers were strained the energetic cost of changing the bond lengths became significantly weaker in other words under enough stress the emergent soft mode encourages the atoms to rearrange themselves into unstable configurations.
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.
when they created the smallest-ever quantum dots single atom of silicon measuring less than one nanometre widesing a technique that will be awarded a U s. patent later this month.
Quantum dots Wolkow says, are vessels that confine electrons, much like pockets on a pool table. The dots can be spaced
observed for the first time how an electrical current flows across the skin of a silicon crystal and also measured electrical resistance as the current moved over a single atomic step.
Wolkow says silicon crystals are mostly smooth except for these atomic staircaseslight imperfections with each step being one atom high.
the research team observed how single electrons jump in and out of the quantum dots, and devised a method of monitoring how many electrons fit in the pocket and measuring the dot's charge.
give scientists the ability to monitor the charge of quantum dots. They've also found a way to create quantum dots that function at room temperature,
meaning costly cryogenics is not necessary.""That's exciting because, suddenly, things that were thought of as exotic,
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.
The team analyzed the solar cell activity of their nanohole interfaces by coating them with a semiconducting polymer and metal electrodes.
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
However this method requires intensive postprocessing (transfer process) as it has to remove used metal after the manufacturing process
After it is done the metal has to be removed and graphene has to be transported to another board.
The research team synthesized a polymer with a rigid ladder structure namely PIM-1 (Polymer of intrinsic microporosity-1) to form the#through the simpole process
"The researchers place the nanowires on the Shrinky Dinks plastic as they would for any other substrate,
"The plastic is clamped before baking so that it only shrinks in one direction, so that the wires pack together
The researchers also can control how densely the wires pack by varying the length of time the plastic is heated.
They also are exploring using lasers to precisely shrink the plastic in specific patterns. Nam first had the idea for using Shrinky Dinks plastic to assemble nanomaterials after seeing a microfluidics device that used channels made of shrinking plastic.
He realized that the high degree of shrinking and the low cost of plastic could have a huge impact on nanowire assembly and processing for applications."
"I'm interested in this concept of synthesizing new materials that are assembled from nanoscale building blocks, "Nam said."
For example, experiments have shown that film made of packed nanowires has properties that differ quite a bit from a crystal thin film."
tubular silica template, starting from commercially available, but nonporous fibers. This template is filled then with a special mixture of carbon, silicon dioxide and surfactants,
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
"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
In 2009, the International Technology Roadmap for Semiconductors (ITRS) selected carbon-based nanoelectronics to include carbon nanotubes
The catalysts, tungsten-based bimetallic alloy nanoparticles of non-cubic symmetry, have high melting points and consequently are able to maintain their crystal structure during the chemical vapor deposition (CVD) process,
to regulate the chirality of the grown SWNTS. The (12,6) SWNTS are synthesized directly at an abundance of>92%by using W6co7 catalysts.
This method is also valid for other tungsten-based alloy nanocatalysts to grow SWNTS of various designed chirality."
"Employing tungsten-based alloy nanocrystals with unique structure as catalysts paves a way for the ultimate chirality control in SWNT growth.
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
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.
We were investigating possible applications for carbon nanotubes in space when we got this result. The effect was confirmed through molecular simulations.
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
While experiments reported in the paper were performed with silverhe most desirable metal because it is the most conductive,
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;
They are made supramolecular constructs up of building blocks called amphiphilic polymers. These nanocarriers hold the guest molecules within the confines of their water-insoluble interior and use their water-soluble exterior to travel through an aqueous environment.
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