#Researchers improve thermal conductivity of common plastic by adding graphene coating (Phys. org) A team of engineering
and physics researchers with members from the U s. the U k. and the Republic of Muldova has found that covering a common type of plastic with a graphene coating can increase its conductivity by up to 600 times.
In their paper published in the journal Nano Letters the team describes their new technique
Conversely graphene is an excellent conductor of heat (in the 2000-5000 W/mk range)
In this new effort the researchers sought to improve heat conduction in a plastic by applying graphene to its surface.
Graphene for the experiment was grown in sheets just a few microns thick and then applied to a thin sheet of PET.
The researchers suggest the graphene coated PET could be used in thermal management applications or thermal lighting
Researchers combine graphene and copper in hopes of shrinking electronics More information: Thermal conductivity of Graphene Laminate Nano Lett. 2014 14 (9) pp 5155-5161.
DOI: 10.1021/nl501996v. On Arxiv: http://arxiv. org/ftp/arxiv/papers/1407/1407.1359. pdfabstractwe have investigated thermal conductivity of graphene laminate films deposited on polyethylene terephthalate substrates.
Two types of graphene laminate were studied as deposited and compressed in order to determine the physical parameters affecting the heat conduction the most.
The measurements were performed using the optothermal Raman technique and a set of suspended samples with the graphene laminate thickness from 9 to 44 m. The thermal conductivity of graphene laminate was found to be in the range from 40 to 90 W/mk at room temperature.
It was found unexpectedly that the average size and the alignment of graphene flakes are more important parameters defining the heat conduction than the mass density of the graphene laminate.
The thermal conductivity scales up linearly with the average graphene flake size in both uncompressed and compressed laminates.
The compressed laminates have higher thermal conductivity for the same average flake size owing to better flake alignment.
Coating plastic materials with thin graphene laminate films that have up to 600 higher thermal conductivity than plastics may have important practical implications s
Published in Nature Nanotechnology researchers from Cardiff University have unveiled a new method for viewing nanodiamonds inside human living cells for purposes of biomedical research.
Nanodiamonds are very small particles (a thousand times smaller than human hair) and because of their low toxicity they can be used as a carrier to transport drugs inside cells.
There is a growing consensus among scientists that nanodiamonds are one of the best inorganic material alternatives for use in biomedical research, because of their compatibility with human cells,
Previous attempts by other research teams to visualise nanodiamonds under powerful light microscopes have run into the obstacle that the diamond material per se is transparent to visible light.
Locating the nanodiamonds under a microscope had relied on tiny defects in the crystal lattice which fluoresce under light illumination.
and in turn the image gleaned from the microscopic exploration of these flawed nanodiamonds, is sometimes also unstable.
In their latest paper, researchers from Cardiff University's Schools of Biosciences and Physics showed that non-fluorescing nanodiamonds (diamonds without defects) can be imaged optically
By focusing these laser beams onto the nanodiamond, a high-resolution CARS image is generated. Using an in-house built microscope,
the research team was able to measure the intensity of the CARS light on a series of single nanodiamonds of different sizes.
The nanodiamond size was measured accurately by means of electron microscopy and other quantitative optical contrast methods developed within the researcher's lab. In this way,
they were able to quantify the relationship between the CARS light intensity and the nanoparticle size.
and number of nanodiamonds that had been delivered into living cells, with a level of accuracy hitherto not achieved by other methods.
The next step for us will be to push the technique to detect nanodiamonds of even smaller sizes than what we have shown so far
Scientists specializing in nanotechnology continue to hunt for the perfect molecular recipe for a battery that drives down price increases durability and offers more miles on every charge.
and anode and leave behind detectable tracks of nanoscale damage. Crucially the high heat of vehicle environments can intensify these telltale degradation tracks and even cause complete battery failure.
and Center for Functional Nanomaterials (CFN) completed a series of three studies each delving deeper into the molecular changes.
These new and fundamental insights may help engineers develop superior battery chemistries or nanoscale architectures that block this degradation.
and suggests new ways to enhance durability including the use of nanoscale coatings that reinforce stable structures.
#Breakthrough in molecular electronics paves the way for DNA-based computer circuits in the future In a paper published today in Nature Nanotechnology,
Molecular electronics, which uses molecules as building blocks for the fabrication of electronic components, was seen as the ultimate solution to the miniaturization challenge.
and devices in the development of programmable circuits, appears in the prestigious journal Nature Nanotechnology under the title"Long-range charge transport in single G-quadruplex DNA molecules."
Porath is affiliated with the Hebrew University's Institute of Chemistry and its Center for Nanoscience and Nanotechnology.
Porath,"This research paves the way for implementing DNA-based programmable circuits for molecular electronics which could lead to a new generation of computer circuits that can be sophisticated more,
#New nanodevice to improve cancer treatment monitoring In less than a minute, a miniature device developed at the University of Montreal can measure a patient's blood for methotrexate, a commonly used but potentially toxic cancer drug.
this nanoscale device has an optical system that can rapidly gauge the optimal dose of methotrexate a patient needs,
Gold nanoparticles on the surface of the receptacle change the colour of the light detected by the instrument.
Roughly, it measures the concentration of serum (or blood) methotrexate through gold nanoparticles on the surface of a receptacle.
the gold nanoparticles change the colour of the light detected by the instrument. And the colour of the light detected reflects the exact concentration of the drug in the blood sample.
We are interested only really in a nanoscale interfacial region and looking at the fluorescence photon signal we can't tell the difference between the interface
because electrons emitted from x-ray excited water molecules travel only nanometer distances through matter. The electrons arriving at the gold electrode surface can be detected as an electrical current traveling through a wire attached to it.
and instruments can separate this nanoampere modulated current from the main Faradaic current. These experiments result in absorption vs. x-ray energy curves (spectra) that reflect how water molecules within nanometers of the gold surface absorb the x-rays.
To translate that information into molecular structure a sophisticated theoretical analysis technique is needed. David Prendergast a staff scientist in the Molecular Foundry and researcher in the Joint Center for Energy storage Research (JCESR) has developed computational techniques that allow his team to accomplish this translation Using supercomputer facilities at Berkeley Lab
and these two layers span only about 1 nanometer. To observe any difference in the experimental spectra with varying voltage means that measurements are sensitive to a shorter length scale than was thought possible.
We had thought the sensitivity to be tens of nanometers but it turns out to be subnanometer says Prendergast.
That's spectacular! This study which is reported in Science in a paper titled The structure of interfacial water on gold electrodes studied by x-ray absorption spectroscopy marks the first time that the scientific community has shown such high sensitivity in an in-situ environment under working electrode conditions s
the idea of a practical manufacturing process based on getting molecules to organize themselves in useful nanoscale shapes seemed...
so that it self-assembles into neat, precise, even rows of alternating composition just 10 or so nanometers wide.
Just recently, Intel Corp. announced that it had in production a new generation of chips with a 14-nanometer minimum feature size.
and in theory, you have a near-perfect pattern for lines spaced 10 to 20 nanometers apart to become, perhaps, part of a transistor array.
The technique can image an area about 500 nanometers across. Between them, the two techniques can yield detailed data on the performance of a given BCP patterning system.
#Nanoparticle technology triples the production of biogas Researchers of the Catalan Institute of Nanoscience and Nanotechnology (ICN2), a Severo Ochoa Centre of Excellence,
which allows increasing the production of biogas by 200%with a controlled introduction of iron oxide nanoparticles to the process of organic waste treatment.
The development of Biogàsplus was carried out by the ICN2's Inorganic nanoparticle group, led by ICREA researcher Víctor Puntes,
The system is based on the use of iron oxide nanoparticles as an additive which"feeds"the bacteria in charge of breaking down organic matter.
and at the same time transforms the iron nanoparticles into innocuous salt.""We believe we are offering a totally innovative approach to the improvement of biogas production and organic waste treatment,
since this is the first nanoparticle application developed with this in mind. In addition, it offers a significant improvement in the decomposition of organic waste
Applied Nanoparticles, a Gateway to the Market"Our idea is the result of many projects:
"We were studying the toxicity of iron oxide nanoparticles in the waste treatment of anaerobic biological processes when we discovered that not only were they not toxic,
With that in mind, they created Applied Nanoparticles, gestated at the ICN2 and currently in the process of signing a knowledge transfer agreement with the UAB."
The grant money went towards testing the capacity of iron oxide nanoparticles, which helped to verify the efficacy of its application in a pilot 100 litre digester.
#Research unlocks potential of super-compound Researchers at The University of Western australia's have discovered that nano-sized fragments of graphene sheets of pure carbon-can speed up the rate of chemical reactions.
because it suggested that graphene might have potential applications in catalysing chemical reactions of industrial importance.
Graphene was one of the most exciting materials to work with in nanotechnology because its two-dimensional structure and unique chemical properties made it a promising candidate for new applications such as energy storage material composites as well as computing
Ever since the discovery of graphene in 2004 scientists have been looking for potential applications in nanochemistry he said.
Using powerful supercomputers researchers at UWA discovered that graphene nanoflakes can significantly enhance the rates of a range of chemical reactions.
Graphene is remarkably strong for its low weight-about 100 times stronger than steel -and it conducts heat and electricity with great efficiency.
The global market for graphene is reported to have reached US$9 million this year with most sales concentrated in the semiconductor electronics battery energy and composites.
Assistant professor Karton said the current investigation showed that graphene nonoflakes could efficiently catalyse a range of chemical reactions.
and extend the scope of the study to'infinite'graphene sheets rather than graphene nanoflakes he said d
#Researchers patent a nanofluid that improves heat conductivity Researchers at the Universitat Jaume I (UJI) have developed
and patented a nanofluid improving thermal conductivity at temperatures up to 400°C without assuming an increase in costs
The nanofluid developed by the Multiphase Fluids research group at the UJI is the first capable of working at high temperatures (up to 400°C
The cost of this new nanofluid (to which nanoparticles are added in order to enhance and improve heat conductivity) is similar to that of the base fluid,
since both the nanoparticles and the stabilizers used are inexpensive. All these features make it suitable for industrial applications that employ heat transmission/exchange systems.
after testing the thermal properties of the nanofluid and patenting this new technology, the research group has started the phase of searching industrial partners
either to transfer the nanofluid over to them or with whom applications can be researched jointly and developed.
and increases the thermal conductivity by adding an exact proportion of nanoparticles consisting on carbon and other additives to the base fluid (diphenyl/diphenyl oxide),
which means that it does not give rise to any problems with pumping, the precipitation of nanoparticles or the obstruction of conduits.
Finally, Juliá notes that the method employed to produce the nanofluid is easily scalable to the industrial level,
the nanofluid developed is based on a heat transfer oil (diphenyl/diphenyl oxide) that is widely used in industry,
because both the nanoparticles and the stabilizers used are abundant, readily accessible and inexpensive e
#Atom-width graphene sensors could provide unprecedented insights into brain structure and function Understanding the anatomical structure
The new device uses graphene a recently discovered form of carbon on a flexible plastic backing that conforms to the shape of tissue.
The graphene sensors are electrically conductive but only 4 atoms thick less than 1 nanometer and hundreds of times thinner than current contacts.
Moreover graphene is nontoxic to biological systems an improvement over previous research into transparent electrical contacts that are much thicker rigid difficult to manufacture and reliant on potentially toxic metal alloys.
graphene which earned researchers the 2010 Nobel prize in Physics; super-resolved fluorescent microscopy which earned researchers the 2014 Nobel prize in Chemistry;
Graphene-based carbon-layered electrode array technology for neural imaging and optogenetic applications. Nature Communications 5 Article number:
#Materials for the next generation of electronics and photovoltaics One of the longstanding problems of working with nanomaterials substances at the molecular and atomic scale is controlling their size.
Hersam a professor of materials science engineering chemistry and medicine at Northwestern University has developed a method to separate nanomaterials by size
The National Science Foundation (NSF)- funded scientist theorized correctly that he could adapt it to separate carbon nanotubes rolled sheets of graphene (a single atomic layer of hexagonally bonded carbon atoms) long recognized for their potential applications in computers
The carbon nanotubes separation process which Hersam developed begins with a centrifuge tube. Into that we load a water based solution and introduce an additive
We then load the carbon nanotubes and put it into the centrifuge which drives the nanotubes through the gradient.
The nanotubes move through the gradient until their density matches that of the gradient. The result is that the nanotubes form separated bands in the centrifuge tube by density.
Since the density of the nanotube is a function of its diameter this method allows separation by diameter.
One property that distinguishes these materials from traditional semiconductors like silicon is that they are mechanically flexible.
Carbon nanotubes are highly resilient Hersam says. That allows us to integrate electronics on flexible substrates like clothing shoes and wrist bands for real time monitoring of biomedical diagnostics and athletic performance.
These materials have the right combination of properties to realize wearable electronics. He and his colleagues also are working on energy technologies such as solar cells
It turns out that carbon nanomaterials are hydrophobic so water will roll right off of them he says.
Materials at the nanometer scale now can realize new properties and combinations of properties that are unprecedented he adds.
Breakthrough for carbon nanotube solar cell l
#See-through one-atom-thick carbon electrodes powerful tool to study brain disorders Researchers from the Perelman School of medicine and School of engineering at the University of Pennsylvania and The Children's Hospital of Philadelphia have used graphene
a two-dimensional form of carbon only one atom thick to fabricate a new type of microelectrode that solves a major problem for investigators looking to understand the intricate circuitry of the brain.
The Center for Neuroengineering and Therapeutics (CNT) under the leadership of senior author Brian Litt Phd has solved this problem with the development of a completely transparent graphene microelectrode that allows for simultaneous optical imaging
and their colleagues Kuzum notes that the team developed a neuroelectrode technology based on graphene to achieve high spatial and temporal resolution simultaneously.
Aside from the obvious benefits of its transparency graphene offers other advantages: It can act as an anti-corrosive for metal surfaces to eliminate all corrosive electrochemical reactions in tissues Kuzum says.
Another advantage of graphene is that it's flexible so we can make very thin flexible electrodes that can hug the neural tissue Kuzum notes.
The graphene microelectrodes developed could have wider application. They can be used in any application that we need to record electrical signals such as cardiac pacemakers
Because of graphene's nonmagnetic and anti-corrosive properties these probes can also be a very promising technology to increase the longevity of neural implants.
Graphene's nonmagnetic characteristics also allow for safe artifact-free MRI reading unlike metallic implants. Kuzum emphasizes that the transparent graphene microelectrode technology was achieved through an interdisciplinary effort of CNT and the departments of Neuroscience Pediatrics and Materials science at Penn and the division of Neurology at CHOP.
Ertugrul Cubukcu's lab at Materials science and engineering Department helped with the graphene processing technology used in fabricating flexible transparent neural electrodes as well as performing optical and materials characterization in collaboration with Euijae Shim and Jason Reed.
The simultaneous imaging and recording experiments involving calcium imaging with confocal and two photon microscopy was performed at Douglas Coulter's Lab at CHOP with Hajime Takano.
The combination of nanocarbon and sulfur is effective at overcoming the insulating nature of sulfur for lithium sulfur batteries."
"Due to excellent electrical conductivity, mechanical strength and chemical stability, nanocarbon materials have played an essential role in the area of advanced energy storage,
Recently, scientists from Tsinghua University have created a freestanding carbon nanotube paper electrode with high sulfur loading for lithium-sulfur batteries.
"We select carbon nanotube (CNT) as the building block",Qiang told Phys. org, "CNTS are one of the most efficient and effective conductive fillers for electrode.
We selected short multi-walled CNTS (MWCNTS) with lengths of 10-50 m as the shortrange electrical conductive network to support sulfur,
as well as super long CNTS with lengths of 1000-2000 m from vertically aligned CNTS (VACNTS) as both long-range conductive networks and inter-penetrated binders for the hierarchical freestanding paper electrode.""
""We develop a bottom-up routine in which sulfur was dispersed firstly well into the MWCNT network to obtain MWCNT@S building blocks
and then MWCNT@S and VACNTS were assembled into macro-CNT-S films via the dispersion in ethanol followed by vacuum filtration",Zhe Yuan,
"Such sulfur electrodes with hierarchical CNT scaffolds can accommodate over 5 to 10 times the sulfur species compared with conventional electrodes on metal foil current collectors
"The areal capacity can be increased further to 15.1 mah cm-2 by stacking three CNT-S paper electrodes, with an areal sulfur loading of 17.3 mg cm-2 as the cathode in a Li
which is also favorable for graphene, CNT-graphene, CNTMETAL oxide based flexible electrodes, "Qiang said."
#New self-assembly method for fabricating graphene nanoribbons First characterized in 2004 graphene is a two-dimensional material with extraordinary properties.
The thickness of just one carbon atom and hundreds of times faster at conducting heat and charge than silicon graphene is expected to revolutionize high-speed transistors in the near future.
Graphene's exotic electronic and magnetic properties can be tailored by cutting large sheets of the material down to ribbons of specific lengths
and edge configurations scientists have theorized that nanoribbons with zigzag edges are the most magnetic making them suitable for spintronics applications.
Now scientists from UCLA and Tohoku University have discovered a new self-assembly method for producing defect-free graphene nanoribbons with periodic zigzag-edge regions.
In this bottom-up technique researchers use a copper substrate's unique properties to change the way the precursor molecules react to one another as they assemble into graphene nanoribbons.
This allows the scientists to control the nanoribbons'length edge configuration and location on the substrate.
This new method of graphene fabrication by self-assembly is a stepping stone toward the production of self-assembled graphene devices that will vastly improve the performance of data storage circuits batteries and electronics.
Paul Weiss distinguished professor of chemistry and biochemistry and a member of UCLA's California Nanosystems Institute developed the method for producing the nanoribbons with Patrick Han and Taro Hitosugi professors at the Advanced Institute
To make devices out of graphene we need to control its geometric and electronic structures Weiss said.
Making zigzag edges does both of these simultaneously as there are some special properties of graphene nanoribbons with zigzag edges.
Other bottom-up methods of fabricating graphene have been attempted but they have produced bundles of ribbons that need to be isolated subsequently
Our method opens the possibility for self-assembling single-graphene devices at desired locations because of the length and the direction control l
#A simple and versatile way to build 3-dimensional materials of the future Researchers in Japan have developed a novel yet simple technique called diffusion driven layer-by-layer assembly to construct graphene into porous
Graphene is essentially an ultra-thin sheet of carbon and possesses exciting properties such as high mechanical stability and remarkable electrical conductivity.
However the thin structure of graphene also acts as a major obstacle for practical uses. When piecing together these tiny sheets into larger structures the sheets easily stack with one another resulting in a significant loss of unique material properties.
and developed it into a technique to assemble graphene into porous 3d architectures while preventing stacking between the sheets.
By putting graphene oxide (an oxidized form of graphene) into contact with an oppositely charged polymer the two components could form a stable composite layer a process also known as interfacial complexation.
and induce additional reactions which allowed the graphene-based composite to develop into thick multilayered structures.
The resulting products display a foam-like porous structure ideal for maximizing the benefits of graphene with the porosity tunable from ultra-light to highly dense through simple changes in experimental conditions.
While we have demonstrated only the construction of graphene-based structures in this study we strongly believe that the new technique will be able to serve as a general method for the assembly of a much wider range of nanomaterials concluded Franklin Kim the principal investigator of the study y
UC Irvine engineers can continue developing this type of nanotechnology device and potentially many others using a more wide-scale manufacturing process.
Nanotechnologies such as this sensor depend on extremely small nanometer scale building blocks. A nanometer is about 100,000 times smaller than the width of a human hair.
Fabricating on this tiny scale poses huge challenges, since most of the current methods that achieve a high level of precision are too costly and slow to be viable for manufacturing."
"With support from the NSF and input from industry, our goal is to help nanoscale manufacturing processes leave the laboratory where they've been confined
and become usable in widespread commercial applications, "said Ragan, associate professor of chemical engineering & materials science and principal investigator on the project.
This grant highlights the strength of our faculty in both nanosciences and advanced manufacturing,"said Gregory Washington, dean of The Henry Samueli School of engineering."
Brighter new energy saving flat panel lights based on carbon nanotubes Even as the 2014 Nobel prize in Physics has enshrined light emitting diodes (LEDS) as the single most significant and disruptive energy-efficient lighting solution of today scientists
Electronics based on carbon especially carbon nanotubes (CNTS) are emerging as successors to silicon for making semiconductor materials.
Scientists from Tohoku University in Japan have developed a new type of energy-efficient flat light source based on carbon nanotubes with very low power consumption of around 0. 1 Watt for every hour's operation
and optimization of the device which is based on a phosphor screen and single-walled carbon nanotubes as electrodes in a diode structure.
They assembled the device from a mixture liquid containing highly crystalline single-walled carbon nanotubes dispersed in an organic solvent mixed with a soap-like chemical known as a surfactant.
The new devices have luminescence systems that function more like cathode ray tubes with carbon nanotubes acting as cathodes
Under a strong electric field the cathode emits tight high-speed beams of electrons through its sharp nanotube tips a phenomenon called field emission.
We have found that a cathode with highly crystalline single-walled carbon nanotubes and an anode with the improved phosphor screen in our diode structure obtained no flicker field emission current and good brightness homogeneity Shimoi said.
In recent years carbon nanotubes have emerged as a promising material of electron field emitters owing to their nanoscale needle shape and extraordinary properties of chemical stability thermal conductivity and mechanical strength.
Highly crystalline single-walled carbon nanotubes (HCSWCNT) have nearly zero defects in the carbon network on the surface Shimoi explained.
The resistance of cathode electrode with highly crystalline single-walled carbon nanotube is very low. Thus the new flat-panel device has compared smaller energy loss with other current lighting devices
Many researchers have attempted to construct light sources with carbon nanotubes as field emitter Shimoi said. But nobody has developed an equivalent and simpler lighting device.
%The two findings have been published simultaneously today in the journal Nature Nanotechnology. For quantum computing to become a reality we need to operate the bits with very low error rates says Scientia Professor Andrew Dzurak who is Director of the Australian National Fabrication Facility at UNSW where the devices were made.
Storing quantum information for 30 seconds in a nanoelectronic device Nature Nanotechnology DOI: 10.1038/nnano. 2014.211 An addressable quantum dot qubit with fault-tolerant control-fidelity Nature Nanotechnology DOI:
10.1038/nnano. 2014.21 1
#DNA nanofoundries cast custom-shaped 3-D metal nanoparticles Researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard university have unveiled a new method to form tiny 3d metal nanoparticles
in prescribed shapes and dimensions using DNA Nature's building block as a construction mold. The ability to mold inorganic nanoparticles out of materials such as gold and silver in precisely designed 3-D shapes is a significant breakthrough that has the potential to advance laser technology microscopy solar cells electronics environmental testing
disease detection and more. We built tiny foundries made of stiff DNA to fabricate metal nanoparticles in exact three-dimensional shapes that we digitally planned
and designed said Peng Yin senior author of the paper Wyss core faculty member and Assistant professor of Systems Biology at Harvard Medical school.
The paper's findings describe a significant advance in DNA NANOTECHNOLOGY as well as in inorganic nanoparticle synthesis Yin said.
For the very first time a general strategy to manufacture inorganic nanoparticles with user-specified 3d shapes has been achieved to produce particles as small as 25 nanometers or less with remarkable precision (less than 5 nanometers.
A sheet of paper is approximately 100000 nanometers thick. The 3d inorganic nanoparticles are conceived first and meticulously planned using computer design software.
Using the software the researchers design three-dimensional frameworks of the desired size and shape built from linear DNA sequences
It is this ability to design arbitrary nanostructures using DNA manipulation that inspired the Wyss team to envision using these DNA structures as practical foundries or molds for inorganic substances.
and expanded to fill all existing space within the DNA framework resulting in a cuboid nanoparticle with the same dimensions as its mold. with the length width
Next researchers fabricated varied 3d polygonal shapes spheres and more ambitious structures such as a 3d Y-shaped nanoparticle and another structure comprising a cuboid shape sandwiched between two spheres proving that structurally-diverse
nanoparticles could be shaped using complex DNA mold designs. Given their unthinkably small size it may come as a surprise that stiff DNA molds are proportionally quite robust and strong able to withstand the pressures of expanding inorganic materials.
Although the team selected gold seedlings to cast their nanoparticles there is a wide range of inorganic nanoparticles that can be shaped forcibly through this process of DNA nanocasting.
A very useful property is that once cast these nanoparticles can retain the framework of the DNA mold as an outer coating enabling additional surface modification with impressive nanoscale precision.
For particles that would better serve their purpose by being as electrically conducive as possible such as in very small nanocomputers
and re-imagined for the nanomanufacturing of inorganic materials said Don Ingber Wyss Institute founding director.
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