Synopsis: Domenii: Materials:

#DNA helps nanoparticle crystals self-assemble Northwestern University rightoriginal Studyposted by Megan Fellman-Northwestern on December 2 2013using the same structure found in nature researchers have built the first near-perfect single crystals

and DNA. ingle crystals are the backbone of many things we rely onâ##diamonds for beauty as well as industrial applications sapphires for lasers

and silicon for electronicssays nanoscientist Chad A. Mirkin. he precise placement of atoms within a well-defined lattice defines these high-quality crystals. ow we can do the same with nanomaterials

research group developed the ecipefor using nanomaterials as atoms DNA as bonds and a little heat to form tiny crystals.

This single-crystal recipe builds on superlattice techniques Mirkin s lab has been developing for nearly two decades.

and professor of materials science and engineering in the Mccormick School of engineering and Applied science to evaluate the new technique

and shape of crystals they can build. The team worked with gold nanoparticles but the recipe can be applied to a variety of materials with potential applications in the fields of materials science photonics electronics

and catalysis. A single crystal has order: its crystal lattice is continuous and unbroken throughout. The absence of defects in the material can give these crystals unique mechanical optical and electrical properties making them very desirable.

In the study strands of COMPLEMENTARY DNA act as bonds between disordered gold nanoparticles transforming them into an orderly crystal.

The researchers determined that the ratio of the DNA linker s length to the size of the nanoparticle is critical. f you get the right ratio it makes a perfect crystalâ##isn t that fun?

We are learning so many rules for calculating things that other people cannot compute in atoms in atomic crystals. he ratio affects the energy of the faces of the crystals

and result in a sphere not a faceted crystal she explained. With the correct ratio the energies fluctuate less

and result in a crystal every time. magine having a million balls of two colors some red some blue in a container

and link togetherhe says. hey beautifully assemble into a three-dimensional crystal that we predicted computationally

and realized experimentally. o achieve a self-assembling single crystal in the lab the research team reports taking two sets of gold nanoparticles outfitted with COMPLEMENTARY DNA

Working with approximately 1 million nanoparticles in water they heated the solution to a temperature just above the DNA linkers melting point

The very slow cooling process encouraged the single stranded-dna DNA to find its complement resulting in a high-quality single crystal approximately three microns wide. he process gives the system enough time

There s no reason we can t grow extraordinarily large single crystals in the future using modifications of our techniquesays Mirkin who also is a professor of medicine chemical and biological engineering biomedical engineering and materials science and engineering and director of the university s International Institute for Nanotechnology.

and Fermi-edge singularities a process known to occur in metals. The team previously reported the first observation of superfluorescence in a solid-state system by strongly exciting semiconductor quantum wells in high magnetic fields.

The secret is a stretchy polymer that coats the electrode binds it together and spontaneously heals tiny cracks that develop during battery operation. elf-healing is very important for the survival and long lifetimes of animals

so they will have a long lifetime as well. ang developed the self-healing polymer in the lab of Zhenan Bao a professor of chemical engineering at Stanford

For the battery project Chao added tiny nanoparticles of carbon to the polymer so it would conduct electricity. e found that silicon electrodes lasted 10 times longer

when coated with the self-healing polymer which repaired any cracks within just a few hoursbao says. heir capacity for storing energy is in the practical range now

Attached to each of the cyclic peptides are two different types of polymers which tend to de-mix

and polymers. anus nanotubes are a versatile platform for the design of exciting materials which have a wide range of application from membranesâ##for instance for the purification of waterâ##to therapeutic uses including the development of new drug systems. ource:

#Crystal structure could push the limits of solar cells University of Pennsylvania right Original Studyposted by Evan Lerner-Pennsylvania on November 13 2013 A new model for solar cell construction may ultimately make them less expensive easier to manufacture

and of materials science and engineering at the University of Pennsylvania. e call this the bulk photovoltaic effect rather than the interface effect that happens in existing solar cells.

The resulting crystal would ideally have the structure of the parent but with elements from the second material in key locations enabling it to absorb visible light. he design challengesays Peter K. Davies chair of the department of materials science and engineering as to identify materials that could retain their polar properties while simultaneously absorbing visible light.

The theoretical calculations pointed to new families of materials where this often mutually exclusive combination of properties could in fact be stabilized. his structure is something known as a perovskite crystal.

Most light absorbing materials have a symmetrical crystal structure meaning their atoms are arranged in repeating patterns up down left right front and back.

A perovskite crystal has the same cubic lattice of metal atoms but inside of each cube is an octahedron of oxygen atoms

when you have a material with two metals and oxygen. It's not something we had to architect ourselves. fter several failed attempts to physically produce the specific perovskite crystals they had theorized the researchers succeeded with a combination of potassium niobate the parent polar material and barium nickel niobate

which contributes to the final product's bandgap. The researchers used X-ray crystallography and Raman scattering spectroscopy to ensure they had produced the crystal structure and symmetry they intended.

They also investigated its switchable polarity and bandgap showing that they could indeed produce a bulk photovoltaic effect with visible light opening the possibility of breaking the Shockley-Queisser limit.

With reflective pigments mixing blue and yellow yields green; however with emissive light mixing such complementary colors yields white.

Until recently the preparation of phosphor materials was more an art than a science based on finding crystal structures that act as hosts to activator ions

and stabilize the sulfur the researchers used amylopectin a polysaccharide that s a main component of corn starch. he corn starch can effectively wrap the graphene oxide-sulfide composite through the hydrogen bonding to confine the polysulfide among the carbon layerssays Hao Chen

to make lithium-sulfur cathodes by synthesizing a nanocomposite consisting of sulfur coated with a common inexpensive conductive polymer called polyaniline and

Similar sulfur-polyaniline composites have previously been synthesized in a ore-shellstructure but the new method provides an internal void within the polymer shell called a olk-shellstructure. hen the lithium-sulfur battery was discharged fully the volume of the sulfur expanded dramatically to 200 percent.

If you think about the beauty of an egg yolk there is some empty space inside with space for the yolk to expandyu says.

while simultaneously suppressing nonlinear scattering from oceanic bubbles. Leightonâ#team proposed that the TWIPS method could be applied to electromagnetic waves

#Ceramic converter tackles solar cell problem Stanford university rightoriginal Studyposted by Mark Shwartz-Stanford on October 21 2013coating a solar cell component in ceramics makes it more heat resistant

but in practice they don t achieve thatsays study co-author Paul Braun a professor of materials science at Illinois. hat s

When subjected to temperatures of 1800 F (1000 C) the ceramic-coated emitters retained their structural integrity for more than 12 hours.

The ceramic-coated emitters were sent to Fan and his colleagues at Stanford who confirmed that devices were still capable of producing infrared light waves that are ideal for running solar cells. hese results are unprecedentedsays former Illinois graduate student Kevin Arpin the lead author of the study. e demonstrated for the first time that ceramics

could help advance thermophotovoltaics as well other areas of research including energy harvesting from waste heat high-temperature catalysis

is established well. opefully these results will motivate the thermophotovoltaics community to take another look at ceramics

#Nanoribbon material keeps gases captive Rice university rightoriginal Studyposted by Mike Williams-Rice on October 11 2013an enhanced polymer could make vehicles that run on compressed natural gas more practical and even prolong the shelf life of bottled beer

and far lighter than the metal in tanks now used to contain the gas say researchers.

By adding modified single-atom-thick graphene nanoribbons (GNRS) to thermoplastic polyurethane (TPU) the team at Rice made it 1000 times harder for gas molecules to escape Tour says.

The researchers led by Rice graduate student Changsheng Xiang produced thin films of the composite material by solution casting GNRS treated with hexadecane and TPU a block copolymer of polyurethane that combines hard and soft materials.

The GNRS geometry makes them far better than graphene sheets for processing into composites Tour says.

Stress and strain tests also found that the 0. 5 percent ratio was optimal for enhancing the polymer s strength. he idea is to increase the toughness of the tank

but a glass bottle until they figured out how to modify plastic to contain the carbon dioxide bubbles.

and in some ways it s the reverse problemhe says. xygen molecules get in through plastic and make the beer go bad.

#At super high temps, white graphene stops rust Atomically thin sheets of hexagonal boron nitride (h-BN) have the handy benefit of protecting

and materials science at Rice university. verybody has been talking about these materials for electronic or photonic devices but if this can be realized on a large scale it'#going to cover a broad spectrum of applications. ltrathin h-BN protection might find a place in turbines jet engines oil exploration

and steel with similar results. hat's amazing is that these layers are ultra thin

and materials science and of chemistry. t a few nanometers wide they'##re a totally noninvasive coating.

materials science. ecause it employs commercial lasers and low-cost mass-production techniques the researchers believe it will set the stage for new generations of abletopaccelerators.

The researchers were able to stabilize the light s frequency by developing a silica glass chip resonator with a specially designed path for the photons in the shape of

In addition to its use as a frequency reference for lasers a reference cavity could one day play a role equivalent to that of the ubiquitous quartz crystal in electronics.

Stanford university rightoriginal Studyposted by Tom Abate-Stanford on September 27 2013engineers have built a basic computer using carbon nanotubes a success that points to a potentially faster more efficient alternative to silicon chips.

Mihail Roco a senior advisor for nanotechnology at the National Science Foundation called the work n important scientific breakthrough. t was roughly 15 years ago that carbon nanotubes were fashioned first into transistors the on-off switches

But a bedeviling array of imperfections in these carbon nanotubes has frustrated long efforts to build complex circuits using CNTS.

and low-power switching make carbon nanotubes excellent candidates to serve as electronic transistors. NTS could take us at least an order of magnitude in performance beyond where you can project silicon could take uswong said.

Depending on how the CNTS grow a fraction of these carbon nanotubes can end up behaving like metallic wires that always conduct electricity instead of acting like semiconductors that can be switched off.

beyond silicon. hese are initial necessary steps in taking carbon nanotubes from the chemistry lab to a real environmentsays Supratik Guha director of physical sciences for IBM s Thomas J. Watson Research center

but silver is too expensive for use at large scalesays Yi Cui an associate professor of materials science and engineering. hough the search is under way for a more practical material finding a substitute will take time. ource:

#Ink-jet printing creates soft nanostructures A new way to make nanostructures combines advanced ink-jet printing technology with block copolymers that spontaneously form ultra-fine structures.

The ability to fabricate nanostructures out of polymers DNA proteins and other oftmaterials has the potential to enable new classes of electronics diagnostic devices and chemical sensors.

but there are significant challenges in achieving true nanoscale dimension. ur work demonstrates that processes of polymer self-assembly can provide a way around this limitationsays John Rogers professor of materials science and engineering at University of Illinois at Urbana-Champaign.

Combining jet printing with self-assembling block copolymers enabled the engineers to attain the much higher resolution as suggested by lead author Serdar Onses a postdoctoral scientist at Illinois. Onses earned his doctorate at the University of Wisconsin

Back at the University of Illinois engineers place a block copolymer atop this pattern. The block copolymer self-organizes directed by the underlying template to form patterns that are at much higher resolution than the template itself.

Previous work has focused on the deposition and assembly of uniform films on each wafer or substrate resulting in patterns with essentially only one characteristic feature size

But practical applications may need block copolymers of multiple dimensions patterned or spatially placed over a wafer. his invention to use ink-jet printing to deposit different block copolymer films with high spatial resolution over the substrate is highly enabling in terms of device design

and manufacturing in that you can realize different dimension structures all in one layernealey says. oreover the different dimension patterns may actually be directed to assemble with either the same

or different templates in different regions. he advanced form of ink-jet printing the engineers use to locally deposit block copolymers is called electrohydrodynamic or e-jet printing.

##and manmade products constructed from similar materials has to do with the hierarchical architecture of the biological materialsâ##the way the silica-based skeletons are built up from different structural elements some

Julia R. Greer professor of materials science and mechanics at the California Institute of technology (Caltech) says the work was inspired by earlier work to fabricate extremely lightweight microtrusses. e designed architectures with building blocks that are less than five microns

For example Greer s group has shown previously that at the nanoscale some metals are about 50 times stronger than usual

and say that I want something that has this strength or this thermal conductivity for example. Then I can design the optimal architecture with the optimal material at the relevant size

Next the researchers used a technique called two-photon lithography to turn that design into a three-dimensional polymer lattice.

Then they uniformly coated that polymer lattice with thin layers of the ceramic material titanium nitride (Tin)

and removed the polymer core leaving a ceramic nanolattice. The lattice is constructed of hollow struts with walls no thicker than 75 nanometers. e are now able to design exactly the structure that we want to replicate

and then process it in such a way that it s made out of almost any material class we d likeâ##for example metals ceramics

In the Nature Materials work the team tested the individual octahedral cells of the final ceramic lattice

and found that they had an unusually high tensile strength. Despite being subjected repeatedly to stress the lattice cells did not break

Typical ceramics fail because of flawsâ##the imperfections such as holes and voids that they contain. e believe the greater strength of these nanostructured materials comes from the fact that

For the purposes of this experiment the researchers placed silica##manganese oxide eadson the matchstick material and introduced hydrogen peroxide as the chemical fuel in one particular place.

They placed the atchsticksin a mixture alongside ordinary polymer microspheres. When the hydrogen peroxide was added the microspheres continued to move in the direction of convection currents

Clay has high thermal stability, high sorption capacity, a large active surface area and high permeability, Reddy says,

and is used commonly in muds for oil drilling, in modern construction, in medical applications and as a binder by iron and steel foundries.

After combining equal amounts of RTIL and naturally occurring Bentonite clay into a composite paste

and combined the RTIL/clay with a small amount of thermoplastic polyurethane to form a membrane sheet that can be cut into various shapes and sizes,

Weighing in at two thirds less than aluminum magnesium is the lightest structural metal. But the usefulness of the metal is restricted severely by its poor resistance to corrosion.

Research efforts to develop lighter metals have explored way to create a stainless or corrosion-resistant form of magnesium.

A team led by Nick Birbilis an associate professor of materials engineering at Monash University found that the addition of very low levels of arsenic to magnesium retards the corrosion reaction by effectively#poisoning#the reaction before it completes.

#In an era of light-weighting for energy and emissions reductions there is a great demand for magnesium alloys in everything from portable electronics to air

The arsenic effect we discovered is now being trialed as a functional additive to existing commercial alloys.#

Ice would reduce the coefficient of friction on the slopes of crater rims increasing the likelihood of a slide.

The researchers point out the work is a tarting point for exploring the composites made from GNRS and other transition metal oxides for lithium storage applications.

or mechanical peeling, from a crystal of graphite. But exfoliation is a time-consuming process that will never be practical for any of the many potential applications of graphene that require industrial mass production. httpv://www. youtube. com/watch?

is about 90 percent as strong as the ideal crystal. his is an exciting result for the future of graphene,

or more in size, says Hone. his strength will be invaluable as scientists continue to develop new flexible electronics and ultrastrong composite materials.

or ultrastrong composites that could replace carbon fiber. Or, the researchers speculate, a science fiction idea of a space elevator that could connect an orbiting satellite to Earth by a long cord that might consist of sheets of CVD graphene,

since graphene (and its cousin material, carbon nanotubes) is the only material with the high strength-to-weight ratio required for this kind of hypothetical application.

#For the study published online in the Journal of the American Ceramic Society Jackson and colleagues characterized samples of Roman concrete taken from a breakwater in Pozzuoli Bay near Naples Italy.#

or carpets#says lead researcher Miriam Rafailovich professor of materials science and engineering and co-director in the program of chemical and molecular engineering at Stony Brook University.

and five times as long#made of a layer of gold bonded to a layer of silicon nitride.

The researchers chose these materials because of their different thermal expansion coefficients a parameter that determines how much a material will expand when heated.

Because metals will naturally convert some energy from infrared light into heat researchers can connect the amount the material expands to the amount of infrared light hitting it.#

since gold has the higher thermal expansion coefficient and will expand more.##To measure this movement the researchers used a fiber interferometer.

A fiber optic cable pointed upward at this system bounces light off the underside of the silicon nitride layer enabling the researchers to determine how far the structure has bent upwards.#

Light hits a shallow tank of liquid plastic and cures it one layer at a time, slowly building up an entire 3d object.

which print layers of melted plastic that then hardens, DLP machines print upside down. The printed object base adheres to a flat metal sheet that slowly raises out of the tank of liquid.

Xian-Ming Bai, Richard G. Hoagland and Blas P. Uberuaga of the Materials science and Technology Division;

each sensor utilizes an array of tens of thousands of carbon nanotubes, which have had copper atoms attached to them.

Tiny beads of polystyrene are used also, which absorb ethylene and concentrate it near the nanotubes.

Normally, the fungus feeds on chitin and breaks it down into monomer amino sugars. With the addition of the new genes,

Known as the Octopus Siphon Actuator the miniature prototype system consists of four joined 20 x 6-cm (7. 9 x 2. 4-in) elastomer balls

This is called nacre (also known as mother-of-pearl) and it's what gives the shell its strength#the outer surface of the shell is made almost entirely of calcium carbonate

Fran#ois Barthelat studied the internal structure of nacre which is comprised of individual microscopic tablets that interlock in a fashion similar to Lego blocks.

and is also planning on applying it to other brittle materials such as ceramics and polymers.

Its composite-bladed turbine starts generating electricity at a minimum wind speed of 1. 7 meters (5. 6 ft) per second,

Products that use silica-based nanoparticles for biomedical uses such as various chips drug or gene delivery and tracking imaging ultrasound therapy and diagnostics may also pose an increased cardiovascular

and interaction of silica-based nanoparticles with biological systems write the researchers. Because our research demonstrates a clear cardiovascular health risk associated with this trend steps need to be taken to help ensure that potential health

The implant consists of a stretchy silicone substrate covered in cracked-gold conducting tracks leading to electrodes made from a silicon/platinum microbead composite.

such as"ninja polymers"and artificial nanoparticles made of lipids. But this latest breakthrough by researchers from Novobiotic in Cambridge, Massachusetts, Northeastern University in Boston, the University of Bonn in Germany,

which is exposed to different types of pollution from agrochemical residues to metals from leather tanneries.

#ISAAC robot joins NASA to weave advanced composites The robot revolution continues at NASA this month as its Langley Research center in Hampton,

Virginia prepares to bring its Integrated Structural Assembly of Advanced Composites (ISAAC) robot online. One of only three robots like it in the world,

it will be formally commissioned on January 26 before being put to work making lighter, stronger composite components for aerospace vehicles.

but fabricating composites was not one of its strengths. What was needed was a versatile, flexible machine that can change functions quickly.

According to NASA, more conventional composite manufacturing requires these ribbons to be laid down at one of three angles 0 degrees, 45, or 90.

NASA says that this versatility will not only help in creating better composites but it will also speed up the prototyping process As well as ISAAC begins work on the Aeronautics Research Mission Directorate Advanced Composites Project and the Space technology Mission Directoratecomposites for Exploration Upper Stage,

it will not only be able to create scale models for wind tunnel tests, but even fan blades for the wind tunnel itself.

but by and large these objects are made still solely of dumb plastic. This may be about to change thanks to the Voxel8 a printer presented at CES that makes it much easier to blend plastic conductive ink

The only two printing materials currently supported are standard PLA plastic and the silver conductive ink but the startup has said users will be able to upgrade their printer in the future as more functional

and polymer layers where the light is collected. Furthermore, graphics can be printed to improve its visual appearance.

#Polymer gel that stores light energy A team led by Nicolas Giuseppone, professor at the Université de Strasbourg,

at CNRS Institut Charles Sadron, has developed a polymer gel that is able to contract through the action of artificial molecular motors.

these nanoscale motors twist the polymer chains in the gel, which as a result contracts by several centimeters.

which cross-link the polymer chains to each other, by rotating molecular motors made up of two parts that can turn relative to each other when provided with energy.

as soon as the motors are activated by light they twist the polymer chains in the gel, which makes it contract.

it is turned into mechanical energy through the twisting of the polymer chains, and stored in the gel.

the amount of energy contained in the contraction of the polymer chains becomes very high,

Local and state seizures without federal participation amounted to 57 percent of the dollar value of the seized items under Equitable Sharing since 2008$3 billion out of $5. 3 billon.

I. Kim is affiliated also with the Neuroscience Program the Institute for Genomic Biology the Beckman Institute and the departments of bioengineering of materials science and engineering and of nuclear plasma and radiological engineering at the U. of I d

#Explosives and Pesticides Can Be detected by Using Bee venom Scientists from MIT have discovered that by coating carbon nanotubes in bee venom,

##Wu, who is a member of both Berkeley Lab and the Berkeley University s Materials science and engineering department,

For when heated, vanadium dioxide s crystals begin to rapidly contract along one dimension, while expanding along the other two,

#At lunch, eating teriyaki chicken out of a styrofoam container from the deli by the bus station felt like heaven compared with the slog of the day.

##Researchers at#USC s Viterbi School of Engineeringhave created a#functioning synapse#using neurons made from carbon nanotubes.

which sand, heated to its melting point, cools into solid glass. With enough sun, a large lens and an ample supply of sand, he figured he might be able to produce glassware.

#Scientists develop new liquid metal that will let you print circuits on paper, T-shirts, or even leaves Soon we could be able to print circuits as well as 3-D products in the comfort of our homes.

Three scientists in China have found a#way#to create a metal that s liquid at room temperatures,

that could be printed on glass or transparent plastic. The key innovation, MIT Technologyreview#says, is the alloy of gallium and indium that the scientists discovered.

It s printable at room temperature, while many other printable circuit inks require high temperatures##up to 400 degrees Celsius,

##Different from the former direct writing technology where large surface tension and poor adhesion between the liquid metal and the substrate often impede the flexible printing process,

the liquid metal here no longer needs to be oxidized pre to guarantee its applicability on target substrates,##Qin Zhang, Yunxia Gao,

and Jing Liu,#the three scientists, write. The technology behind this innovation is##cheap and simple,

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