patterned silica material laid on top of a traditional solar cell. The material is transparent to the visible sunlight that powers solar cells,
Despite the high performance of metallic implants, including titanium and its alloys, in human body, the relatively weak corrosion resistance of the implants in the body and their inappropriate compatibility has resulted in a great challenge in the application of metallic alloys.
Therefore, Iranian researchers studied a type of composite nanocoating to obtain modified properties of biomaterials to be used in human body.
when the amount of diopside added to the base of hydroxyapatite increases up to 30 weight percent, the size of final composite grain and its size distribution significantly decreases after two steps of sintering process.
because the optimum conditions for applying nanocomposite coating through electrophoretic method on metals are obtained at low particle size distributions s
X-ray crystallography and cryo-electron microscopy to discover the tiny structural details of biomolecules. All these methods,
The synthesis of these fabrics will open new windows to the production of composites with conventional and innovative applications.
The researchers believe their new method is compatible with roll-to-roll manufacturing--an existing method for creating devices in bulk using a roll of flexible plastic and a processing machine.
industrial-quality metal deposited on polymer sheets. First, an electronic mechanical cutter is used to form patterns on the metal-polymer sheets.
Second, after removing excessive areas, the electronics are printed onto any polymer adhesives, including temporary tattoo films.
The cutter is programmable so the size of the patch and pattern can be customized easily.
some of the atoms in the anode--an electrically conductive metal like lithium--become ions that then travel to the cathode,
#Graphene teams up with two-dimensional crystals for faster data communications Ultra-fast detection of light lies at the heart of optical communication systems nowadays.
the research group led by Prof at ICFO Frank Koppens has shown that a two-dimensional crystal, combined with graphene,
but related two-dimensional crystals were still lagging very much behind. In our work we show that by teaming up these two materials,
and magnetic materials interact with each other due to their opposite magnetic ordering direction of magnetization: in magnetic layers storages the magnetic field tends to arrange spins in one direction,
"made of nanolayers of ferromagnetic material, superconductor and other metals. By changing the direction of magnetization it is possible to control the current in superconductor.
and transition metal dichalcogenides,"said Awschalom.""It's not just that it's faster and easier.
#Single atom alloy platinum-copper catalysts cut costs, boost green technology: New generation of catalysts demonstrated for selective hydrogenation of butadiene Abstract:
for example in polymer electrolyte membrane (PEM) fuel cells, which are the leading contenders for small-scale and mobile power generation not based on batteries or combustion engines.
in order to facilitate downstream polymer production. The current industrial catalyst for butadiene hydrogenation uses palladium and silver.
while a relatively cheap metal, is not nearly as catalytically powerful as platinum, noted Professor of Chemistry Charles Sykes, Ph d.,one of the senior authors on the paper."
"The researchers first conducted surface science experiments to study precisely how platinum and copper metals mix."
"We were excited to find that the platinum metal dissolved in copper, just like sugar in hot coffee, all the way down to single atoms.
We call such materials single atom alloys, "said Sykes. The Tufts chemists used a specialized low temperature scanning tunneling microscope to visualize the single platinum atoms and their interaction with hydrogen."
such as platinum-copper single atom alloy nanoparticles supported on an alumina substrate, and then tested them under industrial pressure and temperatures."
We believe this approach is also applicable to other precious metals if added as minority components in copper."
In the early 2000s, Maria's group had pioneered the single-atom approach for metals anchored on oxide supports as the exclusive active sites for the water-gas shift reaction to upgrade hydrogen streams for fuel cell use.
Together we embarked on a new direction involving single atom alloys as catalysts for selective hydrogenation reactions.
"Sykes and Flytzani-Stephanopoulos have used this approach to design a variety of single atom alloy catalysts that have,
and properties of single atom alloy surfaces and then applied this knowledge to develop a working catalyst.
The researchers make the film by first using a nanolithography developed in Chang's lab to create highly-ordered pores in a polymer substrate.
That porous polymer then serves as a template, which the researchers coats with a thin layer of aluminum oxide using atomic layer deposition.
The polymer is burned then off leaving behind a three-dimensional aluminum oxide coating.""We are able to control the thickness of the aluminum oxide,
"Using zinc oxide in the same process, we can create a thicker coating. And the thickness of the coating controls
usually a transition metal oxide. If a voltage is applied then, the ohmic resistance of the storage cell changes.
According to the researchers, the aim of the research was to prepare an injectable paste made of bioglass and sodium alginate polymer with biocompatibility properties.
Results of the research have been published in Journal of the Australian Ceramics Society vol. 51, issue 2, 2015, pp. 99-108 8
Finding could have implications for high-temperature superconductivity A team of physicists led by Caltech's David Hsieh has discovered an unusual form of matter--not a conventional metal, insulator,
first consider a crystal with electrons moving around throughout its interior. Under certain conditions, it can be energetically favorable for these electrical charges to pile up in a regular,
repeating fashion inside the crystal, forming what is called a charge-ordered phase. The building block of this type of order, namely charge, is simply a scalar quantity--that is,
When spins line up parallel to each other (in a crystal, for example), they form a ferromagnet--the type of magnet you might use on your refrigerator
The Hsieh group's experiment exploited the fact that changes in the symmetry of a crystal will affect the strength of each harmonic differently.
Since the emergence of multipolar ordering changes the symmetry of the crystal in a very specific way--a way that can be largely invisible to conventional probes--their idea was that the optical harmonic response of a crystal could serve as a fingerprint of multipolar order."
"We found that light reflected at the second harmonic frequency revealed a set of symmetries completely different from those of the known crystal structure,
of metal-organic frameworks (MOFS)- sponge-like 3d crystals with an extraordinarily large internal surface area-that feature flexible gas-adsorbing pores.
"Long is the corresponding author of a Nature paper that describes this work entitled,"Methane storage in flexible metal-organic frameworks with intrinsic thermal management."
because the gas must force its way into the MOF crystal structure, opening and expanding the pores.
"In addition, Long says, the step in the adsorption isotherm is associated with a structural phase change in the MOF crystal that reduces the amount of heat released upon filling the tank,
The synthesized magnetic composite is separated from the solution phase in the presence of a magnetic field in a short time through this method.
Results showed that the synthesized composite can be used as an effective sorbent to purify water contaminated by fluoride due to its simple and quick separation, high efficiency and the lack of the creation of secondary pollution in the solution.
The composite can be reused even after five times of application and it can be recycled only by using acidic solution.
#New metal-organic framework material captures carbon at half the energy cost UC Berkeley chemists have made a major leap forward in carbon-capture technology with a material that can
Diamine-Appended Metal-Organic Frameworks The diamine-appended metal-organic framework before and after binding of carbon dioxide.
MOFS are composites of metals--in this case magnesium or manganese--with organic compounds that, together, form a porous structure with microscopic, parallel channels.
Several years ago, Long and his lab colleagues developed a way to attach amines to the metals in an MOF to produce pores of sufficient diameter to allow CO2 to penetrate rapidly into the material.
The pressure at which CO2 binds to the amines can be adjusted by changing the metal in the MOF.
Accion propellant is a liquid salt material, similar in structure to common table salt, which can be made in large quantities.
one that would create designer colors without the use of chemical dyes and pigments. Rather than controlling the chemical composition of a material,
Its flexibility was imparted by embedding the silicon bars into a flexible layer of silicone. As the silicone was bent
or flexed, the period of the grating spacings responded in kind. The semiconductor material also allowed the team to create a skin that was incredibly thin, perfectly flat,
Additionally, ZDDP does not work as well on the lightweight engine materials eyed as potential replacements for steels."
and quickly wear down due to very high local stresses through direct steel-on-steel contacts. The resulting debris can further increase the friction between the surfaces
"The film that grows is not as stiff as the steel. When you push on a stiff surface,
The team demonstrated efficient optical coupling of an array of silicon waveguides to a substrate containing an array of polymer waveguides.
The significant size difference between the silicon waveguides and the polymer waveguides originally presented a major challenge.
The researchers overcame this obstacle by gradually tapering the silicon waveguide, leading to an efficient transfer of the optical signal to the polymer waveguide.
including elastomers, silicones, nylon-like materials, ceramics and biodegradable materials. The technique itself provides a blueprint for synthesizing novel materials that can further research in materials science.
"Now Gorodetsky has fabricated reflectin films on conformable polymer substrates, effectively sticky tape one might find in any household.
In the journal, ACS Nano("Protease-Mediated Release of Chemotherapeutics from Mesoporous Silica Nanoparticles to ex Vivo Human and Mouse Lung Tumors"),the scientists reported that this approach led to a significant increase
#Artificial hand able to respond sensitively thanks to muscles made from smart metal wires Engineers at Saarland University have taken a leaf out of natures book by equipping an artificial hand with muscles made from shape-memory wire.
and the Center for Mechatronics and Automation Technology (Zema) is using a new technology based on the shape memory properties of nickel-titanium alloy.
Shape-memory alloy (SMA) wires offer significant advantages over other techniques, says Stefan Seelecke. Up until now, artificial hands,
the crystal structure reverts back to its austenitic phase, which causes the material to cool down and further absorb heat from its surroundings.
The team's work is the first demonstration that shows elastocaloric materials such as a nickel-titanium (Ni-Ti) alloy can be loaded cyclically
Tuek and colleagues also stabilized the Ni-Ti alloy to ensure a reproducible effect, which is crucial for practical applications,
and created a uniform elastocaloric effect for the alloy. While heat pumps, air conditioners and refrigerators are most likely to benefit from elastocaloric technology,
than a sensor made with the most advanced man-made water-absorbing polymers. There was also better sensitivity in extreme low-pressure, low-humidity situations."
Today reverse-osmosis filters are typically polymers. A filter is thin and resides on a support.
A porous graphene membrane could be more permeable than a polymer membrane, so separated water would drive faster through the membrane under the same conditions, the scientists reasoned."
The researchers transferred the graphene membrane to a silicon nitride support with a micrometer-sized hole.
The silicon nitride chip held the graphene membrane in place while water flowed through it from one chamber to the other.
There has been considerable recent work on using magnetite to clean up toxic metals. For example, magnetite can reduce the toxic form of chromium, chromium VI, to the less toxic chromium (III),
In an experiment, recently published in Science("Probing Johnson noise and ballistic transport in normal metals with a single-spin qubit),
In contrast, a single crystal is uniform at these length scales and electrons can travel over 100 times farther.
and corresponding magnetic field noise from the single silver crystal is a departure from so-called Ohmic predictions of the polycrystalline case,
'In contrast to wood, this material is electrically conductive thanks to the nanotubes, and interestingly the conductivity is temperature-dependent and extremely sensitive,
#Soft, energy-efficient robotic wings Dielectric elastomers are novel materials for making actuators or motors with soft and lightweight properties that can undergo large active deformations with high-energy conversion efficiencies.
This has made dielectric elastomers popular for creating devices such as robotic hands, soft robots, tunable lenses and pneumatic valves--and possibly flapping robotic wings.
Reporting this week in the journal Applied Physics Letters("Phenomena of nonlinear oscillation and special resonance of a dielectric elastomer minimum energy structure rotary joint"),researchers from the Harbin Institute of technology in Weihai, China
Los angeles (UCLA), have discovered a new resonance phenomenon in a dielectric elastomer rotary joint that can make the artificial joint bend up and down,
Jianwen Zhao/Harbin Institute of technology in Weihai, University of California-Los angeles)" The dielectric elastomer is a kind of electro-active polymer that can deform
He said that most studies on dielectric elastomers are using a static or stable voltage to stimulate the joint motion,
"Zhao said this new phenomenon makes the dielectric elastomer joint a good candidate for creating a soft and lightweight flapping wing for robotic birds,
which would be more efficient than bird wings based on electrical motors due to the higher energy conversion efficiency (60 to 90 percent) of the dielectric elastomer.
Dielectric elastomers, due to their soft and lightweight inherent properties and superior electromechanical performances, are considered as a kind of material close to human muscles
Made by sandwiching a soft insulating elastomer film between two compliant electrodes, dielectric elastomers can be squeezed
and expanded in a plane when a voltage is applied between electrodes. In contrast to actuators based on rigid materials such as silicon, dielectric elastomers can reach a very large extent of stretch, often exceeding 100 percent elongation while not breaking,
enabling new possibilities in many fields including soft robotics, tunable optics, and cell manipulation. The dielectric elastomer actuator Zhao used is called a"dielectric elastomer minimum-energy structure"
which is composed of a thin elastic frame and pre-stretched dielectric elastomer films, Zhao said. After adhering the pre-stretched film to the thin elastic frame,
the restoring force of the dielectric elastomer film bends the elastic frame, balancing at a minimum energy state.
When applying kilovolts of low-current electricity on the dielectric elastomer, the frame flattens out and the bending angle decreases.
To restrict frame bending to only one axis, two stiffening frames are mounted to the primary frame as rigid nonbending edges,
which makes dielectric elastomer minimum-energy structures a useful structure for fabricating soft devices, Zhao said.
After experimenting with various parameters such as voltage values, frequencies and the joint mass in the dielectric elastomer joint system,
Also, since dielectric elastomers feature high energy density (seventy times higher than conventional electromagnetic actuators) and high-energy conversion efficiency (60 to 90 percent), they could be good candidates for making energy-efficient devices,
The researchers'next step is to improve the function of the dielectric elastomer rotary joint and refine the fabrication technique to make a real flapping wing g
In actual alloy nanowires though, atoms of the same element might cluster together to form short sections composed of the same elements.
"Their results suggest that heat conduction in a nanowire does not just depend on the relative concentrations of the alloy atoms and the difference in their masses;
high-frequency phonons could travel much further than the average length of the ordered regions in the alloy.
In contrast, a random distribution of alloy atoms resulted in a higher resistance over triple that of the ordered case for a 2. 5-micrometer-long wire.
If this disorder can be realized in real composite materials then we could tailor the thermal conductivity of the system,
The researchers hope their model will help scientists design composite materials with low thermal conductivity. One attractive application is thermoelectric devices,
when moved from water to an electrolyte solution, such as salt water("Dual hydrophilic and salt responsive schizophrenic block copolymers synthesis and study of self-assembly behavior").
Materials composed of segments of two different monomers, each with different characteristics, are known as block copolymers.
Vivek Vasantha at A*STAR Institute of Chemical and Engineering sciences together with scientists from across Singapore under the Innovative Marine Antifouling Solutions (IMAS) program developed a new block copolymer that can self-assemble into spherical micelle structures in
which one monomer forms the core and the other forms the outer shell. The monomers are the hydrophilic poly (ethylene glycol
or PEG, which mixes well with water, and the halophilic polysulfabetaine (PSB), which has a preference for salt solution. e created salt-responsive block copolymers that self-assemble in water to form either onventionalor nversemicelles, states Vasantha.
The conventional micelles form in deionized water and have a core of halophilic PSB with a hydrophilic PEG shell.
However, the team showed that the micelles reassemble themselves when immersed in salt solution; PEG formed the core,
The researchers mixed the block copolymers with primer to create a nontoxic coating to replace traditional antifouling paint.
They constructed the outer layer out of cationicor positively chargedsegments of the polymers. For inside the carrier, they secured the drug with hydrophobic and ph-responsive polymers.
The positively charged outer layer of the carrier is able to stay in place at the surface of the teeth
because the enamel is made up, in part of HA (hydroxyapatite), which is negatively charged. Just as oppositely charged magnets are attracted to each other,
or Antimony-Telluride (Sb2te3) alloys and had a peak efficiency (zt) of 1. 1, meaning the electricity going in was only slightly less than the heat coming out.
Since the 1960's there have been incremental advancements in alloy technology used in Peltier devices.
and Materials science department at California Institute of technology California, USA have formulated a new method for creating a novel and much more efficient TE alloy.
TE alloys are special because the metals have an incredibly high melting point. Instead of melting the metals to fuse them,
they are combined through a process called sintering which uses heat and/or pressure to join the small,
metallic granules. The joint team, including IBS researchers, used a process called liquid-flow assisted sintering
which combined all three antimony, bismuth and telluride granules into one alloy (Bi0. 5sb1. 5te3).
Additional melted tellurium was used as the liquid between the Bi0. 5sb1. 5te3 granules to help fuse them into a solid alloy,
Institute for Basic Science) By creating the alloy this way, the joints between the fused grains,
This new thermoelectric alloy paves the way for the future of modern TE devices s
Polycarbonate skeleton of robot, testing apparatus, fully blown membrane (last two pix. click on image to enlarge) This ground-breaking research was published in Bioinspiration
The end result is a polycarbonate 3d printed streamlined skeleton which had no moving parts (Fig. 1) and no energy storage device other than a thin elastic outer membrane.
If you put polymer chains on the surface that are attracted to the solvent, the particles will bounce off each other
Synthetic diamonds with nitrogen vacancies (NVS) defects that are extremely sensitive to magnetic fields have held long promise as the basis for efficient, portable magnetometers.
and boron nitride (Nanowerk News) The research group led by Professor Yuichi Ikuhara (also appointed as a professor at Tokyo University), Associate professor Zhongchang Wang and Assistant professor Chunlin Chen at the Advanced Institute for Materials Research
in collaboration with Group Leader Takashi Taniguchi at the National Institute for Materials science (NIMS) and Japan Fine Ceramics Center (JFCC), succeeded for the first time in identifying the atomic structure and bonding mechanism in coherent interfaces between diamond
, the hardest known material, and cubic boron nitride, the second hardest, using a state-of-the-art super-high-resolution scanning transmission electron microscope and first-principles calculation.
The research group has attempted to develop new functional materials by focusing on lattice defects in crystals
and extensive theoretical calculation based on first principles, the group revealed that in coherent interfaces between diamond and cubic boron nitride,
This study was published in the online version of the UK scientific journal Nature Communications("Misfit accommodation mechanism at the heterointerface between diamond and cubic boron nitride
shape and size of the polymers. Based on these findings, the team developed a new photolithographic technology that enabled the production of micropatterns with three-dimensional structures in various shapes and sizes.
and thus control the shape and size of the polymer. The use of the polymerization inhibitors enabled
and facilitated the fabrication of complex, three-dimensional micropatterns. Professor Kim said, hile 3d printing is considered an innovative manufacturing technology,
His newest technology will enhance the manufacturing process of three-dimensional polymers which were considered difficult to be commercialized.
and optimal precious metal use. Researchers are optimistic that the approach can be applied readily to other multimetallic catalysts
ACS (click on image to enlarge) The researchers investigated the polymer xylan which comprises a third of wood matter.
"Using advanced NMR techniques we found that the xylan polymer, which comprises about a third of wood,
has unexpected an shape inside the plant cell walls"."The structure of the xylan was ascertained by creating 2d maps of the molecular structure of the woody stalks of thale cress in the UKS most advanced solid-state Nuclear Magnetic resonance (NMR) Facility, based at the University of Warwick.
Using atomic force microscopy the researchers identified that at around 120 C in the crystal formed a bilayer crystal phase.
resulting from the phase transition from a monolayer to a bilayer crystal structure in mono-alkylated liquid crystalline molecules may lead to the possibility of designing new materials for the burgeoning field of printed electronics."
and single-crystal structures of the ac (middle) and ab planes (bottom). Right: Output characteristics of FETS fabricated using the polycrystalline thin films as-coated (top)
Background Small-molecule versus polymer FETS The main issues around organic semiconductor FETS with small molecules are the low thermal durability.
Attempts to use polymers with benzene-like delocalised electron bonding alleviated issues around the thermal durability to a certain extent.
such as reproducible synthesis and purification of the polymers, as well as control of crystallinity and the molecular orientations towards both the substrate surface and the electrodes.
the researchers concluded that crystal-to-crystal phase change from a monolayer to a bilayer structure was improved responsible for the transistor performance in annealed devices s
ITBM, Nagoya University) Metal-catalyzed C-H borylation of aromatic rings is considered an efficient way to introduce functional groups to make functional molecules via a boryl moiety.
#Lanthanide-organic framework nanothermometers prepared by spray-drying A work in Advanced Functional Materials shows how spray-drying prepared MOF nanoparticles containing lanthanide metals may be used as nanothermometers operative over a wide range of temperatures
the first lanthanide-organic framework prepared by the spray-drying method. This system is the most sensitive cryogenic nanothermometer reported so far
but lets water through (Nanowerk News) The unassuming piece of stainless steel mesh in a lab at The Ohio State university doesn't look like a very big deal,
Bhushan and postdoctoral researcher Philip Brown chose to cover a bumpy surface with a polymer embedded with molecules of surfactant--the stuff that gives cleaning power to soap and detergent.
They sprayed a fine dusting of silica nanoparticles onto the stainless steel mesh to create a randomly bumpy surface
and layered the polymer and surfactant on top. The silica surfactant, polymer, and stainless steel are all nontoxic
and relatively inexpensive, said Brown. He estimated that a larger mesh net could be created for less than a dollar per square foot.
Because the coating is only a few hundred nanometers (billionths of a meter) thick, it is mostly undetectable.
To the touch, the coated mesh doesn't feel any bumpier than uncoated mesh. The coated mesh is a little less shiny,
The researchers chose silica in part because it is an ingredient in glass, and they wanted to explore this technology's potential for creating smudge-free glass coatings.
Rather than silica, he experiments with molybdenum disulfide nanotubes, which mix well with oil. The nanotubes are approximately a thousand times smaller than a human hair.
who is the senior author of a paper describing the new sensor this week in the journal Angewandte Chemie("Single-Walled carbon nanotube/Metalloporphyrin Composites for the Chemiresistive Detection of Amines and Meat Spoilage").
In this case, the researchers modified the carbon nanotubes with metal-containing compounds called metalloporphyrins, which contain a central metal atom bound to several nitrogen-containing rings.
Hemoglobin, which carries oxygen in the blood, is a metalloporphyrin with iron as the central atom.
"Bimetallic lanthanide complexes that display a ratiometric response to oxygen concentration"in the periodical Chemical sciences and"Spectrally resolved confocal microscopy using lanthanide centred near-IR emission"in Chemical Communications.
so called lanthanides. One lanthanide, europium, emits a constant red signal. The other, terbium, emits a green signal that increases with diminishing oxygen concentrations.
Most physicians should be able to read the oxygen concentration with the naked eye, explains Thomas Just Sørensen."
They have developed touch-sensitive stickers made from flexible silicone and electrically conducting sensors that can be worn on the skin.
The silicone used to fabricate the sensor patches makes them flexible and stretchable. his makes them easier to use in an everyday environment.
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