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Researchers create artificial protein to control assembly of buckyballs

Researchers create artificial protein to control assembly of buckyballs | Amazing Science | Scoop.it

"This is a proof-of-principle study demonstrating that proteins can be used as effective vehicles for organizing nano-materials by design," says senior author Gevorg Grigoryan, an assistant professor of computer science at Dartmouth. "If we learn to do this more generally - the programmable self-assembly of precisely organized molecular building blocks—this will lead to a range of new materials towards a host of applications, from medicine to energy."

 

The study appears in the journal in Nature Communications.

According to the U.S. National Nanotechnology Initiative, scientists and engineers are finding a wide variety of ways to deliberately make materials at the nanoscale - or the atomic and molecular level—to take advantage of their enhanced properties such as higher strength, lighter weight, increased control of light spectrum and greater chemical reactivity than their larger-scale counterparts.

 

Proteins are "smart" molecules, encoded by our genes, which organize and orchestrate essentially all molecular processes in our cells. The goal of the new study was to create an artificial protein that would self-organize into a new material—an atomically periodic lattice of buckminster fullerene molecules.

 

Buckminster fullerene (buckyball for short) is a sphere-like molecule composed of 60 carbon atoms shaped like a soccer ball. Buckyballs have an array of unusual properties, which have excited scientists for several decades because of their potential applications. Buckyballs are currently used in nanotechology due to their high heat resistance and electrical superconductivity, but the molecule is difficult to organize in desired ways, which hampers its use in the development of novel materials.

 

In their new research, Grigoryan and his colleagues show that their artificial protein does interact with buckyball and indeed does organize it into a lattice. Further, they determined the 3-dimensional structure of this lattice, which represents the first ever atomistic view of a protein/buckyball complex."Learning to engineer self-assembly would enable the precise organization of molecules by design to create matter with tailored properties," Grigoryan says.

 

"In this research, we demonstrate that proteins can direct the self-assembly of buckminsterfullerene into ordered superstructures. Further, excitingly, we have observed this protein/buckyball lattice conducts electricity, something that the protein-alone lattice does not do. Thus, we are beginning to see emergent material behaviors that can arise from combing the fascinating properties of buckyball and the abilities of proteins to organize matter at the atomic scale. Taken together, our findings suggest a new means of organizing fullerene molecules into a rich variety of lattices to generate new properties by design."

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The Atom Without Properties

The Atom Without Properties | Amazing Science | Scoop.it
The microscopic world is governed by the rules of quantum mechanics, where the properties of a particle can be completely undetermined and yet strongly correlated with those of other particles. Physicists from the University of Basel have observed these so-called Bell correlations for the first time between hundreds of atoms. Their findings are published in the scientific journal Science.

 

Everyday objects possess properties independently of each other and regardless of whether we observe them or not. Einstein famously asked whether the moon still exists if no one is there to look at it; we answer with a resounding yes. This apparent certainty does not exist in the realm of small particles. The location, speed or magnetic moment of an atom can be entirely indeterminate and yet still depend greatly on the measurements of other distant atoms.

 

With the (false) assumption that atoms possess their properties independently of measurements and independently of each other, a so-called Bell inequality can be derived. If it is violated by the results of an experiment, it follows that the properties of the atoms must be interdependent. This is described as Bell correlations between atoms, which also imply that each atom takes on its properties only at the moment of the measurement. Before the measurement, these properties are not only unknown -- they do not even exist.

 

A team of researchers led by professors Nicolas Sangouard and Philipp Treutlein from the University of Basel, along with colleagues from Singapore, have now observed these Bell correlations for the first time in a relatively large system, specifically among 480 atoms in a Bose-Einstein condensate. Earlier experiments showed Bell correlations with a maximum of four light particles or 14 atoms. The results mean that these peculiar quantum effects may also play a role in larger systems.

 

In order to observe Bell correlations in systems consisting of many particles, the researchers first had to develop a new method that does not require measuring each particle individually – which would require a level of control beyond what is currently possible. The team succeeded in this task with the help of a Bell inequality that was only recently discovered. The Basel researchers tested their method in the lab with small clouds of ultracold atoms cooled with laser light down to a few billionths of a degree above absolute zero. The atoms in the cloud constantly collide, causing their magnetic moments to become slowly entangled. When this entanglement reaches a certain magnitude, Bell correlations can be detected. Author Roman Schmied explains: “One would expect that random collisions simply cause disorder. Instead, the quantum-mechanical properties become entangled so strongly that they violate classical statistics.”

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Chemical composition of dust from beyond the solar system analyzed

Chemical composition of dust from beyond the solar system analyzed | Amazing Science | Scoop.it
A Heidelberg-designed dust detector on the Cassini space probe -- known as the cosmic dust analyser (CDA) -- has identified several extremely rare and minuscule particles of interstellar dust from outside our solar system, and examined their chemical composition. Surprisingly it turns out that the different dust particles are very similar in composition and have collected the whole element mix of the cosmos. The experts therefore suspect that dust is continually destroyed, reformed and thereby homogenised in the "witch's cauldron" of outer space. The results of an international research team, including scientists from the Institute of Earth Sciences and the Klaus Tschira Laboratory for Cosmochemistry of Heidelberg University, are published in "Science."

"Interstellar dust is one of the last bastions of the unknown in space, its individual particles being only about 200 nanometres in size and very hard to find," explains Prof. Dr. Mario Trieloff, earth scientist from Heidelberg University. The dust is part of the interstellar material consisting of gas and helium, as well as heavy metals, and which can arise from the condensation processes of stars and planets. These particles are the raw material that were the main building blocks for Earth and other terrestrial planets.

When it comes to studying interstellar dust, science has so far depended on particles reaching our solar system. The Stardust space probe was already able to capture particles of the very weak flux crossing our solar system. "But these particles were unusually large, so the research findings are possibly not representative," Prof. Trieloff says. By contrast, the Cassini probe could identify 36 particles of interstellar dust among millions of planetary dust particles. Furthermore the CDA is in a position to analyse them on the spot with the assistance of mass spectrometry. This has enabled much more precise results than before.

Dr. Frank Postberg, on a Heisenberg grant at the Institute for Earth Science, notes that mass spectrometric measurements can now be made for the first time on "a statistically significant quantity of such dust particles." This process had only become possible through a complex series of tests conducted in Heidelberg to calibrate laboratory models of the CDA. To achieve this aim, silicate dust had to be accelerated in the laboratory to upwards of 40 km a second, which is roughly the speed of interstellar dust.

"The result of the measurements was truly amazing," Dr. Postberg reports. "The 36 particles of interstellar origin, that are very similar in their composition, contain a mix of the most important rock-forming elements -- magnesium, iron, silicon and calcium -- in average cosmic abundance.
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Compounds containing an all-metal antiaromatic ring isolated for the first time

Compounds containing an all-metal antiaromatic ring isolated for the first time | Amazing Science | Scoop.it

An international research team has prepared a set of lanthanide antimony clusters that represent the first isolable compounds containing an all-metal antiaromatic ring. The achievement continues to expand the concept of aromaticity beyond its humble beginnings 150 years ago.

 

Researchers including Xue Min and Zhong-Ming Sun of Changchun Institute of Applied Chemistry and Ivan A. Popov and Alexander I. Boldyrev of Utah State University created a series of anions, [Ln(Sb4)3]3–, where Ln is La, Y, Ho, Er, or Lu. They made the anions by treating lanthanide benzyl complexes with the Zintl cluster complex K5Sb4 in pyridine solvent and then isolating them as potassium cryptand salts.

 

The concept of antiaromaticity has a storied history. In 1865, German chemist August Kekulé proposed the concept of aromaticity to explain the unusual properties of benzene, a planar carbon ring that exhibits high stability and low reactivity. In 1931, German chemist Erich Hückel added to the definition that aromatic compounds have a delocalized 4n + 2 π-electron system.

 

In 1965, on the centennial of Kekulé’s concept, Columbia University’s Ronald Breslowproposed the idea of antiaromaticity—the antonym of aromaticity—to characterize planar carbon rings with a 4-electron system that exhibit low stability and high reactivity.

 

Aromaticity and antiaromaticity were originally thought to be purely the domain of organic chemistry. But over the past 20 years chemists have shown that this organic boundary is flexible. In 1995, Gregory H. Robinson and coworkers of the University of Georgia prepared a phenyl-substituted Ga3 ring with 2 π electrons isolated as a sodium salt, introducing the concept of metalloaromaticity.

 

In 2003, Boldyrev’s group in collaboration with Lai-Sheng Wang, now at Brown University, followed suit by reporting Li3Al4–, which includes an antiaromatic Al44– ring containing 4 πelectrons. However, the gaseous molecule was created in a laser-based experiment and couldn’t be trapped in a condensed state.

 

With the [Ln(Sb4)3]3– series, chemists now have the first examples of isolable inorganic antiaromatic compounds. As a key feature, each Sb4 ring stabilized by the lanthanide metal has 4 delocalized π electrons. The Sb4 unit is analogous to cyclobutadiene, Boldyrev says, which is the quintessential antiaromatic organic compound.

 

“Antiaromaticity in these all-metal systems is very nice,” Breslow tells C&EN. “It is gratifying to see that our proposal, which was quite unexpected when we first made it for organic systems, has such generality.”

 

Further advances of aromaticity and antiaromaticity into metal territory will be valuable for understanding the properties of metal clusters, bulk metals, and alloys, Boldyrev and Sun add, which could be handy for making thin-film electronic materials.

 

“From a conceptual perspective, this is another example of the concept of aromaticity—in this case antiaromaticity or antimetalloaromaticity—being extended beyond the realm of carbon,” Robinson says. “More important, taking all of this work into consideration, aromaticity and metalloaromaticity seem to be foundational principles throughout the whole of chemistry.”

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Brilliant new blue pigment discovered by accident

Brilliant new blue pigment discovered by accident | Amazing Science | Scoop.it

An accidental discovery in a laboratory at Oregon State University has apparently solved a quest that over thousands of years has absorbed the energies of ancient Egyptians, the Han dynasty in China, Mayan cultures and more – the creation of a near-perfect blue pigment.


Through much of recorded human history, people around the world have sought inorganic compounds that could be used to paint things blue, often with limited success. Most had environmental or durability issues. Cobalt blue, developed in France in the early 1800s, can be carcinogenic. Prussian blue can release cyanide. Other blue pigments are not stable when exposed to heat or acidic conditions.


But chemists at OSU have discovered new compounds based on manganese that should address all of those concerns. They are safer to produce, much more durable, and should lead to more environmentally benign blue pigments than any being used now or in the past.  They can survive at extraordinarily high temperatures and don’t fade after a week in an acid bath.


The findings were just published in the Journal of the American Chemical Society, and a patent has been applied for on the composition of the compound and the process used to create it. The research was funded by the National Science Foundation. “Basically, this was an accidental discovery,” said Mas Subramanian, the Milton Harris Professor of Materials Science in the OSU Department of Chemistry. “We were exploring manganese oxides for some interesting electronic properties they have, something that can be both ferroelectric and ferromagnetic at the same time. Our work had nothing to do with looking for a pigment. “Then one day a graduate student who is working in the project was taking samples out of a very hot furnace while I was walking by, and it was blue, a very beautiful blue,” he said. “I realized immediately that something amazing had happened.”


What had happened, the researchers said, was that at about 1,200 degrees centigrade – almost 2,000 degrees Fahrenheit – this otherwise innocuous manganese oxide turned into a vivid blue compound that could be used to make a pigment able to resist heat and acid, be environmentally benign and cheap to produce from a readily available mineral.


The newest – and possibly the best – blue pigment in world history was born, due to manganese ions being structured in an unusual “trigonal bipyramidal coordination” in the presence of extreme heat.

“Ever since the early Egyptians developed some of the first blue pigments, the pigment industry has been struggling to address problems with safety, toxicity and durability,” Subramanian said.


The pigment may eventually find uses in everything from inkjet printers to automobiles, fine art or house paint, researchers say. The scientists said in their journal article that the new compound yields “a surprisingly intense and bright blue color,” and they have outlined its structure and characteristics in detail. Collaborating on the work were researchers in the Materials Department at the University of California/Santa Barbara.


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Brett Weathers's curator insight, March 12, 2016 9:45 PM

New blue pigment, yay! 

 

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Four new elements earn permanent seats on the periodic table

Four new elements earn permanent seats on the periodic table | Amazing Science | Scoop.it

The seventh row of the periodic table is officially full now. On December 30, 2015, the International Union of Pure and Applied Chemistry announced that a Russian-U.S. collaboration had attained sufficient evidence to claim the discovery of elements 115, 117 and 118. IUPAC awarded credit for the discovery of element 113 to scientists at RIKEN in Wako, Japan (SN Online: 9/27/12). Both groups synthesized the elements by slamming lighter nuclei into each other and tracking the decay of the radioactive superheavy elements that followed.


Researchers at the Joint Institute for Nuclear Research in Dubna, Russia, and Lawrence Livermore National Laboratory in California, which are among the institutions credited with elements 115, 117 and 118, had also laid claim to element 113 after experiments in 2004 (SN: 2/7/04, p. 84) and 2007. But garnering recognition for the three other elements softened the blow, says Dawn Shaughnessy, who leads the experimental nuclear and radiochemistry group at Livermore. “I’m personally very happy with IUPAC’s decision,” she says.


Published reports on the newly recognized elements will appear in early 2016, says IUPAC executive director Lynn Soby. Official recognition of the elements means that their discoverers earn the right to suggest names and symbols. Element 113 will be the first element discovered and named by researchers in Asia.

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Researchers find way to produce large-area graphene 100 times cheaper

Researchers find way to produce large-area graphene 100 times cheaper | Amazing Science | Scoop.it
Graphene has been hailed as a wonder material since it was first isolated from graphite in 2004. Graphene is just a single atom thick but it is flexible, stronger than steel, and capable of efficiently conducting heat and electricity.


However, widespread industrial adoption of graphene has so far been limited by the expense of producing it. Affordable graphene production could lead to a wide range of new technologies reaching the market, including synthetic skin capable of providing sensory feedback to people with limb prostheses.


Researchers at the University of Glasgow have now found a way to produce large sheets of graphene using the same cheap type of copper used to manufacture lithium-ion batteries found in many household devices.


In a new paper published today in the journal Scientific Reports, a team led by Dr Ravinder Dahiya explain how they have been able to produce large-area graphene around 100 times cheaper than ever before. Graphene is often produced by a process known as chemical vapour deposition, or CVD, which turns gaseous reactants into a film of graphene on a special surface known as a substrate.


The research team used a similar process to create high-quality graphene across the surface of commercially-available copper foils of the type often used as the negative electrodes in lithium-ion batteries. The ultra-smooth surface of the copper provided an excellent bed for the graphene to form upon.


They found that the graphene they produced offered a stark improvement in the electrical and optical performance of transistors which they made compared to similar materials produced from the older process.


Dr Dahiya, of the University of Glasgow's School of Engineering, said: "The commercially-available copper we used in our process retails for around one dollar per square metre, compared to around $115 for a similar amount of the copper currently used in graphene production. This more expensive form of copper often required preparation before it can be used, adding further to the cost of the process.

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Researchers observe phase transition thought impossible

Researchers observe phase transition thought impossible | Amazing Science | Scoop.it
An ultrapure material taken to pressures greater than that in the depths of the ocean and chilled to temperatures colder than outer space has revealed an unexpected phase transition that crosses two different phase categories.


A Purdue University-led team of researchers observed electrons transition from a topologically ordered phase to a broken symmetry phase. "To our knowledge, a transition across the two groups of phases had not been unambiguously demonstrated before, and existing theories cannot describe it," said Gábor Csáthy, an associate professor in Purdue's Department of Physics and Astronomy who led the research. "It is something like changing water from liquid to ice; except the two phases we saw were very different from one another."


A paper detailing the results of the Department of Energy and National Science Foundation-funded research will be published in an upcoming issue of Nature Physics and is currently available online.


Csáthy's research team was focusing on the fractional quantum Hall state at quantum number 5/2, which is believed to be a non-Abelian topological phase. Non-Abelian states are different from anything known in nature, he said.


"Imagine eggs in an egg carton as electrons arranged in a certain formation," he said. "The eggs are identical just like the electrons are identical particles. If you swap one egg with another, nothing has changed. It is still a group of eggs in the same formation. If someone did not see the swap, he or she would never know it had happened. In non-Abelian states, if you swap two electrons, it causes a change to the entire group and the egg carton enters an entirely different state. This ability of a swap to affect the state of the entire group is a very special property."


It is thought that if this property could be harnessed, it could be used in quantum computing, he said. The team was trying to induce an electron spin transition in this non-Abelian state, but before the desired state was reached, the electrons spontaneously transitioned into the so-called "stripe" phase that belongs to the traditional, broken symmetry phases group.


"When we started the experiment we were trying to accomplish something else, but the stripes kept popping up and we would lose the fractional quantum Hall phase we were investigating," Csáthy said. "We were very surprised because it was thought that these two different categories of phases were far apart and such a transition was impossible, but the electrons went from deep in the topological phase to deep in the broken symmetry phase."


The team then changed the course of the experiment to go step by step through the new transition. The team next plans to characterize the new phase transition and establish its parameters so that the data can be compared to the developing theories, Csáthy said.

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The rise of X-ray beam chemistry

The rise of X-ray beam chemistry | Amazing Science | Scoop.it
By using powerful photon beams, researchers have shown that they can now control the chemical environment and provide nanoscale structural detail while simultaneously imaging the mineral calcite as it is pushed to its extremes.


For scientists to understand a system, they often push it to its limits. In geochemistry, that means putting minerals under extreme conditions and watching how they react. This can be done in a number of ways, but the approach is usually the same: develop tools necessary to observe reactions in better detail and look at how minerals react when their natural environment is destabilized.


The X-ray Reflection Interfacial Microscope, a new surface microscope at the U.S. Department of Energy's (DOE's) Argonne National Laboratory, has led to a major breakthrough. By using powerful photon beams generated by the Advanced Photon Source (APS), a DOE User Facility located at Argonne, researchers have shown that they can now control the chemical environment and provide nanoscale structural detail while simultaneously imaging the mineral calcite as it is pushed to its extremes.


"There are some very extreme natural environments on our planet," said Argonne's Paul Fenter, Interfacial Processes Group Leader and co-author of the study appearing today in the journal Science. "If you can understand how minerals react at the most extreme conditions, this gives you confidence in our understanding of reactions under less extreme conditions."


Our natural world rests in a delicate balance controlled by the movement of nutrients and toxins through waterways. Minerals like calcite grow and dissolve in response to changes in the water composition, which can be characterized by its level of acidity (i.e., the pH). A key feature of this experiment was the use of the X-rays to drive the calcite out of equilibrium while simultaneously observing how it dissolves.


"These reactions are well-known," said Nouamane Laanait, the paper's first author and current Eugene P. Wigner Fellow at Oak Ridge National Laboratory. "They are the same as those that control how calcite dissolves in oceans in response to increased CO2 levels. This work demonstrates that if one has precise control over the beam probe and appropriate modeling of the beam interactions [with the sample], then one can learn a great deal that would be inaccessible otherwise."


To see what happens to the calcite when it is destabilized, researchers used a technique called X-ray reflection interface microscopy (XRIM) at the APS. Piercing through water solution and reflecting off the calcite's surface like a mirror, focused X-rays changed the water's acidity level, starting a chain of reactions that lowered the pH and caused the calcite to dissolve. Tiny pits, similar to ones observed in previous experiments, began to form with simple round or rectangular shapes. The rate at which these pits formed and grew let researchers know that the X-ray beam was, in fact, controlling the local chemistry as predicted. What they didn't predict came next.


As the X-rays pushed the calcite to more extreme levels of instability, researchers were surprised to see that the dissolving pits became distorted and formed ink splatter-like irregularities, indicating that some parts were dissolving quicker than others. Known as reaction front instabilities, these irregularities had not previously been observed in real time.


"Calcite is well-studied," said Fenter, "and so we have a very good understanding of how it grows and dissolves over a wide range of conditions. That we were able to observe a new mode of dissolution was exciting since it suggests that there is still much to be learned."


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Alayna Anthony's comment, September 29, 2015 7:54 PM
I just couldn't stay focused on this article. I thought it would interest me but to be honest I just didn't like it. I couldn't stay sucked in. It was too scientific to be interesting. There needs to be a balance between interesting and facticious. That's really all I can say about this article.
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The structural memory of water persists on a picosecond timescale

The structural memory of water persists on a picosecond timescale | Amazing Science | Scoop.it

A team of scientists from the Max Planck Institute for Polymer Research (MPI-P) in Mainz, Germany and FOM Institute AMOLF in the Netherlands has characterized the local structural dynamics of liquid water, i.e. how quickly water molecules change their binding state. Using innovative ultrafast vibrational spectroscopies, the researchers show why liquid water is unique when compared to most other molecular liquids. This study has recently been published in the scientific journal Nature Communications.

With the help of a novel combination of ultrafast laser experiments, the scientists found that local structures persist in water for longer than a picosecond, a picosecond (ps) being one thousandth of one billionth of a second (10exp-12  s). This observation changes the general perception of water as a solvent. Water is a very special liquid with extremely fast dynamics. Water molecules wiggle and jiggle on sub-picosecond timescales, which make them undistinguishable on this timescale. While the existence of very short-lived local structures — e.g. two water molecules that are very close to one another, or are very far apart from each other — is known to occur, it was commonly believed that they lose the memory of their local structure within less than 0.1 picoseconds.


The proof for relatively long-lived local structures in liquid water was obtained by measuring the vibrations of the Oxygen-Hydrogen (O-H) bonds in water. For this purpose the team of scientists used ultrafast infrared spectroscopy, particularly focusing on water molecules that are weakly (or strongly) hydrogen-bonded to their neighboring water molecules. The scientists found that the vibrations live much longer (up to about 1 ps) for water molecules with a large separation, than for those that are very close (down to 0.2 ps). In other words, the weakly bound water molecules remain weakly bound for a remarkably long time.

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Morpho butterfly wings help break the status quo in gas sensing

Morpho butterfly wings help break the status quo in gas sensing | Amazing Science | Scoop.it

The unique properties found in the stunning iridescent wings of a tropical blue butterfly could hold the key to developing new highly selective gas detection sensors. Pioneering new research by a team of international scientists, including researchers from the University of Exeter, has replicated the surface chemistry found in the iridescent scales of the Morpho butterfly to create an innovative gas sensor.


The ground-breaking findings could help inspire new designs for sensors that could be used in a range of sectors, including medical diagnostics, industry, and the military.The research, published in the highly respected scientific journal, Nature Communications on September 1st ("Towards outperforming conventional sensor arrays with fabricated individual photonic vapour sensors inspired by Morpho butterflies"), describes how the composition of gases in different environments can be detected by measuring small colour changes of the innovative bio-inspired sensor.


Professor Pete Vukusic, one of the authors of the research and part of the Physics department at the University of Exeter said: "Bio-inspired approaches to the realisation of new technologies are tremendously valuable. In this work, by developing a detailed understanding of the subtle way in which the appearance and colour of the Morpho butterfly arises, and the way this colour depends on its local environment, our team has discovered a remarkable way in which we can advance sensor and detector technology rapidly."


Tiny tree-like nanostructures in the scales of Morpho wings are known to be responsible for the butterfly's brilliant iridescence. Previous studies have shown that vapour molecules adhere differently to the top of these structures than to the bottom due to local chemistry within the scales. This selective response to vapour molecules is the key to this bio-inspired gas sensor.

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Researchers build and morph chemical patterns on stretchable surfaces

Researchers build and morph chemical patterns on stretchable surfaces | Amazing Science | Scoop.it

With just a slight stretch of the imagination -- and some elastic material -- UNL researchers have shown how to fabricate microscopic chemical patterns whose adaptability could extend from the physical to the functional. In a new study, the authors detail a method for synthesizing hundreds of chemically based shapes in any conceivable pattern on silicone rubber films. The study also outlines multiple potential applications for the technique, which could prove useful in areas ranging from chemistry and circuitry to optics and textiles.


The team's technique involves oxidizing the material's surface before attaching amines, ammonia-derived molecules that react with many of the signature atomic groups found in commercially available chemicals. After "drawing" a honeycomb pattern with the amines, the researchers deposited tiny liquid droplets of a chemical compound onto the silicone and watched as they dutifully filled the hexagonal rows outlined by the pattern.


By stretching the silicone film either before or after depositing the liquid, the researchers also demonstrated the ability to morph the size, shape and density of the chemical pattern and its individual droplets. The team found that the pattern quickly reverted to its original form when the material was relaxed to its natural state.


"Anyone who has written a message on a rubber band is familiar with what happens when you stretch it," said Stephen Morin, assistant professor of chemistry and the study's lead author. "In a sense, what we have done here is analogous -- but instead of ink from a marker, we have written our message by selectively attaching molecules to form patterns."


The use of an elastic material affords them far more literal and figurative flexibility when compared with the more labor-intensive techniques for modifying patterns on rigid surfaces, Morin said. "While looking through the (research) literature, we were very surprised to see that there was very little to none that actually coupled the mechanical properties of rubber with its surface-chemical properties," he said. "We are excited by the possibilities. The manipulation of these tiny droplets presents a number of opportunities that haven't been shown before."


Having such rapidly reversible control over the chemistry of a surface could point researchers and engineers toward new ways of controlling material properties, behaviors and applications, Morin said.


The ability to easily morph patterns, for example, might reduce the number of masks needed to filter the light exposures that define circuit layouts in computational components. With more research, it could even allow engineers to fabricate designs at scales smaller than they can easily achieve using current methods, Morin said.


"We can use a single mask as a template for our chemical pattern, but by changing the stress in the material relative to the pattern of the mask, we can access different families of patterns," Morin said. "When you define a pattern (while stretching the film) and then release the material, the features have to get smaller. So you actually can get higher feature density … more simply than by fabricating an entirely new mask."


Morin said the technique could also be used to organize arrays of liquid micro-lenses. Micro-lens arrays can improve the efficiency of optical detectors to produce high-quality digital images favored in professional photography and medicine.

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Ethylenedione (O=C=C=O), an elusive molecule—finally found

Ethylenedione (O=C=C=O), an elusive molecule—finally found | Amazing Science | Scoop.it
Scientists at the University of Arizona have discovered a mysterious molecule with a structure simple enough to make it into high school textbooks, yet so elusive that chemists have argued for more than a century over whether it even exists.


And, like so many important discoveries in science, this one started out with a neglected flask sitting in a storage fridge, in this case in the lab of Andrei Sanov, a professor in the UA's Department of Chemistry and Biochemistry. Sanov and two of his students report the first definitive observation and spectroscopic characterization of ethylenedione, or "OCCO," representing two carbon monoxide molecules chemically bound together. According to the researchers, the interest in this deceptively "simple" compound is fueled by many reasons: from its assumed role as a fleeting intermediate in a flurry of chemical reactions to its alleged properties as a wonder drug.


Forgoing the past synthetic strategies that relied on the manipulation of neutral species, two students in Sanov's laboratory created OCCO from its negatively charged ion and used a highly advanced technique called photoelectron imaging spectroscopy to analyze the product. This technique uses laser pulses to eject electrons from molecules, effectively yielding "a portrait of the molecule viewed from within," as Sanov put it.


The results confirm the existence of the elusive species and reveal its important fundamental properties, with implications not only for the basic understanding of so-called radical molecular species, but also industrial processes and potentially even atmospheric chemistry and climate modeling.


Chemists have pursued the OCCO molecule off and on since 1913, when its existence was first suggested. In the 1940s, at a particularly controversial turn in OCCO's history, it was claimed to be the active component of Glyoxylide, a purported antidote for a long list of afflictions, from exhaustion to cancer. The claims were classified as fraud by the U.S. Food and Drug Administration, because the wonder drug proved to be nothing but water. Nonetheless, to this day the myth of Glyoxylide as a "lost" cancer remedy continues to be perpetuated on the Internet.


According to Sanov, one of the motivations for pursuing ethylenedione is the elegant fundamental puzzle that the molecule presents: Most students with elementary chemistry education can draw the straightforward structure, O=C=C=O. Over the years, the anticipated existence of OCCO also has been backed by predictions of sophisticated theory. However, all past studies failed to provide conclusive experimental evidence that ethylenedione exists—and therein lay the puzzle.


The key to the mystery is the unstable nature of the OCCO, which tends to split into two carbon monoxide (CO) fragments after half a nanosecond or so. OCCO is what chemists call a diradical. Radicals and diradicals play exceptionally important roles in controlling the mechanisms and outcomes of chemical reactions, involved in all aspects of life, industry, technology and environment.


"Radicals and diradicals are all around us," Sanov said. "Think of them as molecules with unpaired electrons that are 'underemployed' and looking for action. This means that they are eager to react, because the making and breaking of chemical bonds is controlled by electrons. A radical is a molecule that has one such 'underemployed' electron. A diradical has two."

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Water molecules confined in nanochannels exhibit quantum tunneling behavior

Water molecules confined in nanochannels exhibit quantum tunneling behavior | Amazing Science | Scoop.it
Water molecules confined in nanochannels exhibit tunneling behavior that smears out the positions of the hydrogen atoms into a pair of corrugated rings.

 

Tunneling is a quantum effect that lets particles go through microscopic barriers in a single bound. A study of water trapped in an emerald-like crystal reveals tunneling of water molecules among multiple orientations, so that each molecule is essentially in six configurations at once. The researchers showed with neutron scattering experiments that the tunneling causes the water’s hydrogen atoms to spread out into ring-like distributions. This new form of water is a more symmetric structure that is predicted to have zero electric dipole moment—the property that normally allows water to form hydrogen bonds and perform well as a solvent.

 

Tunneling occurs when an object traverses a barrier without having enough energy to do so classically. Certain molecules can tunnel among rotational orientations. A representative example is the methyl group (CH3)(CH3), which is a carbon atom bound to three hydrogens in a symmetric pyramid configuration. Electric forces from nearby atoms generate repulsion that resists any rotation around the pyramid axis. However, the hydrogens can tunnel through these barriers from one pyramid corner to the next. This discrete hopping couples together rotational orientations, causing an observable splitting of the ground state into multiple levels with slightly different energies.

 

 Recently, optical spectroscopy revealed energy splitting in the terahertz spectrum of water molecules in the gemstone beryl, suggesting that the molecule is hopping among multiple states [1]. The crystal structure of beryl(Be3Al2Si6O18)(Be3Al2Si6O18) contains channels with hexagonal cross-sections that can trap water molecules. The channels periodically narrow into “cages” roughly 0.5 nanometers wide by 0.9 nanometers long and only big enough for one water molecule. The previously observed splitting suggested that the confined water was rotationally tunneling inside the channels, but a more direct test was necessary. Now Alexander Kolesnikov from Oak Ridge National Laboratory (ORNL) in Tennessee and his colleagues have performed a series of neutron scattering measurements on a beryl sample containing water.

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New world record for fullerene-free polymer solar cells

New world record for fullerene-free polymer solar cells | Amazing Science | Scoop.it
Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences. This work is about avoiding costly and unstable fullerenes.

 

Polymer solar cells have in recent years emerged as a low cost alternative to silicon solar cells. In order to obtain high efficiency, fullerenes are usually required in polymer solar cells to separate charge carriers. However, fullerenes are unstable under illumination, and form large crystals at high temperatures.

 

Now, a team of chemists led by Professor Jianhui Hou at the CAS set a new world record for fullerene-free polymer solar cells by developing a unique combination of a polymer called PBDB-T and a small molecule called ITIC. With this combination, the sun's energy is converted with an efficiency of 11%, a value that strikes most solar cells with fullerenes, and all without fullerenes.

 

Feng Gao, together with his colleagues Olle Inganäs and Deping Qian at Linköping University, have characterized the loss spectroscopy of photovoltage (Voc), a key figure for solar cells, and proposed approaches to further improving the device performance. The two research groups are now presenting their results in the high-profile journal Advanced Materials.

 

We have demonstrated that it is possible to achieve a high efficiency without using fullerene, and that such solar cells are also highly stable to heat. Because solar cells are working under constant solar radiation, good thermal stability is very important, said Feng Gao, a physicist at the Department of Physics, Chemistry and Biology, Linköping University.

 

The combination of high efficiency and good thermal stability suggest that polymer solar cells, which can be easily manufactured using low-cost roll-to-roll printing technology, now come a step closer to commercialization, said Feng Gao.

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Route to Carbyne: Scientists Create Ultra-Long 1D Carbon Chains

Route to Carbyne: Scientists Create Ultra-Long 1D Carbon Chains | Amazing Science | Scoop.it

Even in its elemental form, the high bond versatility of carbon allows for many different well-known materials, including diamond and graphite. A single layer of graphite, named graphene, can then be rolled or folded into carbon nanotubes or fullerenes, respectively. To date, Nobel prizes have been awarded for both graphene and fullerenes.

 

Although the existence of carbyne, an infinitely long carbon chain, was proposed in 1885 by Adolf von Baeyer, scientists have not yet been able to synthesize this material. Von Baeyer even suggested that carbyne (also known as linear acetylenic carbon) would remain elusive as its high reactivity would always lead to its immediate destruction. Nevertheless, carbon chains of increasing length have been successfully synthesized over the last five decades, with a record of around 100 carbon atoms.

To grow even longer carbon chains – up to 6,000 carbon atoms long – on a bulk scale, Dr. Pichler and his colleagues used the confined space inside a double-walled carbon nanotube as a nano-reactor.

 

“The direct experimental proof of confined ultra-long linear carbon chains, which are more than an order of magnitude longer than the longest proven chains so far, can be seen as a promising step towards the final goal of unraveling the ‘holy grail’ of carbon allotropes, carbyne,” said team member Lei Shi, from the Faculty of Physics at the University of Vienna. “Carbyne is very stable inside double-walled carbon nanotubes,” the scientists said. “This property is crucial for its eventual application in future materials and devices.”

 

“According to theoretical models, carbyne’s mechanical properties exceed all known materials, outperforming both graphene and diamond.”

 

“Carbyne’s electrical properties suggest novel nanoelectronic applications in quantum spin transport and magnetic semiconductors.” The results were published online April 4, 2016 in the journal Nature Materials (arXiv.org preprint).

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Molecular surgery stitches up water dimer in fullerene cage | Chemistry World

Molecular surgery stitches up water dimer in fullerene cage | Chemistry World | Amazing Science | Scoop.it

First isolation of dimer to aid fundamental studies of hydrogen bonding. Two molecules of water have been trapped inside a fullerene cage allowing the formation of a hydrogen bond between the two molecules to be observed. It is the first time that the elusive dimer of water has been isolated and could open the way to fundamental studies of hydrogen bonding in water. The technique could also be used to study the interaction of pairs of other species at the single-molecule level, the researchers suggest.

 

‘Monomers and dimers of water are rare,’ says Yasujiro Murata of Kyoto University, Japan, who led the research. ‘A water molecule wants to catch another water molecule to give a dimer, and at the same time the water dimer dissociates into two water molecules. The water dimer also wants to catch another water molecule to give a trimer. Following these processes, water in the gas phase exists as a mixture of oligomers: monomers and dimers are rare.’

 

In the past, a limited number of single atoms and molecules have been trapped in C60 fullerenes, including rare gases, dihydrogen and water. Murata’s team wanted to see if they could trap a single water molecule in the slightly larger cavity of a C70 fullerene.

 

To do this they used a ‘molecular surgical’ method to peel open part of the outer shell of the fullerene through the stepwise cleavage of targeted C=C bonds of the cage, to create an opening large enough for water to enter. They then exposed the ruptured cages to water at high temperature and pressures to try to force a single water molecule into the cage, before selective restoration of the C=C bonds to trap it.

 

The team used HPLC to separate the water-containing cages from those that remained empty. To their surprise, they found that while some cages had trapped a single water molecule, as expected, others had captured two water molecules. ‘We knew that the inner space of C60 was not large enough for two water molecules, and before this study we thought that was also true for C70,’ says Murata. ‘We were very surprised to observe cages containing two trapped water molecules.’

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Single molecule detection of contaminants, explosives or diseases now possible

Single molecule detection of contaminants, explosives or diseases now possible | Amazing Science | Scoop.it

A technique that combines the ultrasensitivity of surface-enhanced Raman scattering (SERS) with a slippery surface invented by Penn State researchers will make it feasible to detect single molecules of a number of chemical and biological species from gaseous, liquid or solid samples. This combination of slippery surface and laser-based spectroscopy will open new applications in analytical chemistry, molecular diagnostics, environmental monitoring and national security.


The researchers, led by Tak-Sing Wong, assistant professor of mechanical engineering and the Wormley Family Early Career Professor in Engineering, call their invention SLIPSERS, which is a combination of Wong’s slippery liquid-infused porous surfaces (SLIPS), a biologically inspired surface based on the Asian pitcher plant, and SERS.


“We have been trying to develop a sensor platform that allows us to detect chemicals or biomolecules at a single-molecule level whether they are dispersed in air, liquid phase, or bound to a solid,” Wong said. “Being able to identify a single molecule is already pretty difficult. Being able to detect those molecules in all three phases, that is really challenging.”


Wong needed the help of postdoctoral fellow Shikuan Yang to combine SERS and SLIPS into a single process. Yang was trained in Raman spectroscopy in the characterization laboratory of Penn State’s Materials Research Institute. His expertise in the SERS technique and Wong’s knowledge of SLIPS enabled them to develop the SLIPSERS technology. Their work appeared online on December 31, 2015 in the Proceedings of the National Academy of Sciences.

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Researchers find new phase of carbon, make diamond at room temperature

Researchers find new phase of carbon, make diamond at room temperature | Amazing Science | Scoop.it
Researchers from North Carolina State University have discovered a new phase of solid carbon, called Q-carbon, which is distinct from the known phases of graphite and diamond. They have also developed a technique for using Q-carbon to make diamond-related structures at room temperature and at ambient atmospheric pressure in air.



Phases are distinct forms of the same material. Graphite is one of the solid phases of carbon; diamond is another. "We've now created a third solid phase of carbon," says Jay Narayan, the John C. Fan, Distinguished Chair Professor of Materials Science and Engineering at NC State and lead author of three papers describing the work.


"The only place it may be found in the natural world would be possibly in the core of some planets." Q-carbon has some unusual characteristics. For one thing, it is ferromagnetic – which other solid forms of carbon are not. "We didn't even think that was possible," Narayan says.


In addition, Q-carbon is harder than diamond, and glows when exposed to even low levels of energy. "Q-carbon's strength and low work-function – its willingness to release electrons – make it very promising for developing new electronic display technologies," Narayan says. But Q-carbon can also be used to create a variety of single-crystal diamond objects.


To understand that, you have to understand the process for creating Q-carbon. Researchers start out with a substrate such as sapphire, glass or a plastic polymer. The substrate is then coated with amorphous carbon – elemental carbon that, unlike graphite or diamond, does not have a regular, well-defined crystalline structure. The carbon is then hit with a single laser pulse lasting approximately 200 nanoseconds. During this pulse, the temperature of the carbon is raised to 4,000 Kelvin (or around 3,727 degrees Celsius) and then rapidly cooled. This operation takes place at one atmosphere – the same pressure as the surrounding air. The end result is a film of Q-carbon, and researchers can control the process to make films between 20 nanometers and 500 nanometers thick.


By using different substrates and changing the duration of the laser pulse, the researchers can also control how quickly the carbon cools. By changing the rate of cooling, they are able to create diamond structures within the Q-carbon. "We can create diamond nanoneedles or microneedles, nanodots, or large-area diamond films, with applications for drug delivery, industrial processes and for creating high-temperature switches and power electronics," Narayan says. "These diamond objects have a single-crystalline structure, making them stronger than polycrystalline materials. And it is all done at room temperature and at ambient atmosphere – we're basically using a laser like the ones used for laser eye surgery. So, not only does this allow us to develop new applications, but the process itself is relatively inexpensive."

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The hole story: Swiss-cheese-like materials called metal–organic frameworks are maturing

The hole story: Swiss-cheese-like materials called metal–organic frameworks are maturing | Amazing Science | Scoop.it
Swiss-cheese-like materials called metal–organic frameworks have long promised to improve gas storage, separation and catalysis. Now they are coming of age.


The crystals are metal–organic frameworks (MOFs), molecular scaffolds made up of metal-containing nodes linked by carbon-based struts (see 'An open box'). The resulting pores are ideal for trapping guest molecules and, in some cases, forcing them to participate in chemical reactions. And they can be tailored with exquisite precision: researchers have created more than 20,000 types of MOF, with potential applications that range from stripping carbon dioxide from power-plant exhausts to separating intractable industrial mixtures, catalysing chemical reactions and revealing molecular structures. “MOFs are the fastest growing class of materials in chemistry today,” says Omar Yaghi, a chemist at the University of California, Berkeley, and one of the pioneers of the field.


MOFs were long thought to be too frail for use in the real world, often collapsing as soon as the guest molecules were removed. Many researchers were sceptical that the products could ever compete against the tough inorganic materials called zeolites, whose pores are exploited in a wide variety of industrial processes, including filtration and catalysis.


But after more than a decade of intensive research in labs around the world, MOFs are poised to make their debut in commercial applications. Although unwilling to reveal the identity of the MOF in question, BASF has said that it is ready to market a methane-storage system this year that can cram in much more fuel than a conventional pressure vessel.


MOF researchers say that this milestone would be a shot in the arm for their work, and potentially help to stimulate commercial interest in the many other applications that are close behind, often from other producers.


Via Jeff Morris
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Graphene nano-coils discovered to be powerful natural electromagnets

Graphene nano-coils discovered to be powerful natural electromagnets | Amazing Science | Scoop.it

Rice University scientists have discovered that a widely used electronic part called a solenoid could be scaled down to nano-size with macro-scale performance. The secret: a spiral form of atom-thin graphene that, remarkably, can be found in nature, even in common coal, according to Rice theoretical physicist Boris Yakobson and his colleagues.


The researchers determined that when a voltage is applied to such a “nano-coil,” current will flow around the helical path and produce a magnetic field, as it does in macroscale solenoids. The discovery is detailed in a new paper in the American Chemical Society journal Nano Letters.


“Perhaps this might work in reverse here: An electron current, pumped through by the applied voltage, at certain conditions may just cause the graphene spiral to spin, like a fast little electro-turbine,” Yakobson speculated.


Solenoids are components with wires coiled around a metallic core. They produce a magnetic field when carrying current, turning them into electromagnets. These are widespread in electronic and mechanical devices, from circuit boards to transformers to carsThey also serve as inductors, which are primary components in electric circuits that regulate current (the lump in power cables that feed electronic devices contains an inductor, which blocks RF interference). In their smallest form, inductors are a part of integrated circuits.


While transistors get steadily smaller, basic inductors in electronics have become relatively bulky, said Fangbo Xu, a Rice alumnus and lead author of the paper. “It’s the same inside the circuits,” he said. “Commercial spiral inductors on silicon occupy excessive area. If realized, graphene nano-solenoids could change that.”


The nano-solenoids analyzed through computer models at Rice should be capable of producing powerful magnetic fields of about 1 tesla, about the same as the coils found in typical loudspeakers, according to Yakobson and his team — and about the same field strength as some MRI machines. They found the magnetic field would be strongest in the hollow, nanometer-wide cavity at the spiral’s center.


The spiral form is attributable to a simple topological trick, he said. Graphene is made of hexagonal arrays of carbon atoms. Malformed hexagons known as dislocations along one edge force the graphene to twist around itself, akin to a continuous nanoribbon that mimics a mathematical construct known as a Riemann surface.


The researchers demonstrated theoretically how energy would flow through the hexagons in nano-solenoids with edges in either armchair or zigzag formations. In one case, they determined the performance of a conventional spiral inductor of 205 microns in diameter could be matched by a nano-solenoid just 70 nanometers wide.


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After more than a century searching, elusive acid finally created

After more than a century searching, elusive acid finally created | Amazing Science | Scoop.it
Cyanoform, a chemical sought for more than a century and written into textbooks, is one of the strongest organic acids.


After more than a century of searching, chemists have finally nabbed a legendary acid. The acid called cyanoform or tricyanomethane appears widely in textbooks as one of the strongest carbon-based acids known. Yet despite attempts to make the acid dating back to 1896, cyanoform has evaded chemists until now. Researchers report September 18 in Angewandte Chemie International Edition that they isolated the acid by figuring out crucial experimental conditions.


The main problem was temperature, says coauthor Andreas Kornath, an inorganic chemist at Ludwig Maximilian University of Munich. Researchers previously assumed that cyanoform is stable at room temperature. “It is just not,” Kornath says.  Using trial and error, he and his team found that cyanoform is stable only below –40°C.


The acid has a central carbon atom attached to a hydrogen atom as well as to three cyano groups, each consisting of a carbon triple-bonded to a nitrogen. The molecule loses its hydrogen atom very easily, making it a strong acid and demonstrating a fundamental rule of carbon acids. The rule describes how electron-loving groups (in this case, the cyano groups) attached to a central hydrogen-toting carbon pull on that carbon’s electrons. The molecule’s electrons settle into a cozy position close to the cyano groups, leaving the link to the hydrogen extremely weak. But at room temperature, cyanoform simply decomposes, quickly forming junk molecules, Kornath says.


This is probably what happened in 1896 when chemist Hermann Schmidtmann tried to make cyanoform. Schmidtmann mixed sulfuric acid with a stable relative of cyanoform called sodium tricyanomethanide. That molecule, considered a salt of cyanoform, has the same structure as the acid except it has lost the positive hydrogen ion, resulting in a negative molecule, which is paired with a positive sodium ion.


Several research groups have tried to isolate cyanoform since, repeating Schmidtmann’s experiment or trying new strategies. All failed until now, says Jack Dunitz, a chemical crystallographer retired from ETH Zurich in Switzerland. Cyanoform has been “listed in all the books,” he says. But “it’s doubtful whether it’s ever been made at room temperature.”


At frigid temperatures, though, Kornath and colleagues finally made the acid, which is a colorless liquid. Similar to Schmidtmann’s method, the researchers reacted a strong acid, in this case hydrogen fluoride, with a salt of cyanoform. Using multiple chemical analyses, they found that the resulting molecule perfectly matched the structure of cyanoform.

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Phagraphene, a new “Relative” of Graphene Discovered

Phagraphene, a new “Relative” of Graphene Discovered | Amazing Science | Scoop.it

A group of scientists from Russia, the USA and China, led by Artyom Oganov from the Moscow Institute of Physics and Technology (MIPT), using computer generated simulation have predicted the existence of a new two-dimensional carbon material, a “patchwork” analogue of graphene called phagraphene. The results of their investigation were recently published in the journal Nano Letters.     


“Unlike graphene, a hexagonal honeycomb structure with atoms of carbon at its junctions, phagraphene consists of penta-, hexa- and heptagonal carbon rings. Its name comes from a contraction of Penta-Hexa-heptA-graphene,” says Oganov, head of the MIPT Laboratory of Computer Design.  


Two-dimensional materials, composed of a one-atom-thick layer, have attracted great attention from scientists in the last few decades.  The first of these materials, graphene, was discovered in 2004 by two MIPT graduates, Andre Geim and Konstantin Novoselov. In 2010 Geim and Novoselov were awarded the Nobel Prize in physics for that achievement.


Due to its two-dimensional structure, graphene has absolutely unique properties. Most materials can transmit electric current when unbound electrons have an energy that corresponds to the conduction band of the material. When there is a gap between the range of possible electron energies, the valence band, and the range of conductivity (the so-called forbidden zone), the material acts as an insulator. When the valence band and conduction band overlap, it acts a conductor, and electrons can move under the influence of electric field.


In graphene each carbon atom has three electrons that are bound to electrons in neighboring atoms, forming chemical bonds. The fourth electron of each atom is “delocalized” throughout the whole graphene sheet, which allows it to conduct electrical current. At the same time, the forbidden zone in the graphene has zero width. If you plot the electron energy and their location in graph form, you get a figure resembling an hour glass, i.e. two cones connected by vertices. These are known as Dirac cones.


Due to this unique condition, electrons in graphene behave very strangely: all of them have one and the same velocity (which is comparable to the velocity of light), and they possess no inertia. They appear to have no mass. And, according to the theory of relativity, particles traveling at the velocity of light must behave in this manner. The velocity of electrons in graphene is about 10 thousand kilometers a second. Electron velocities in a typical conductor vary from centimeters up to hundreds of meters per second.


Phagraphene, discovered by Oganov and his colleagues through the use of the USPEX algorithm, as well as graphene, is a material where Dirac cones appear, and electrons behave similar to particles without mass.

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Self-assembly of molecular Archimedean polyhedra

Self-assembly of molecular Archimedean polyhedra | Amazing Science | Scoop.it
Chemists truly went back to the drawing board to develop new X-shaped organic building blocks that can be linked together by metal ions to form an Archimedean cuboctahedron. In the journal Angewandte Chemie, the scientists report that by changing the concentration or using different counterions, the cuboctahedron can be reversibly split into two octahedra—an interesting new type of fusion–fission switching process.


Archimedean polyhedra are a group of symmetrical solids with regular polygons for faces and equal angles at the vertices, like a classic soccer ball with its 12 pentagons and 20 hexagons. These forms are also found in nature: the rigid shells (capsids) of many viruses, as well as certain cellular transport vesicles are also Archimedean polyhedra. These biological forms are made by the self-assembly of individual protein building blocks. Chemists have frequently turned to this concept for inspiration to synthesize large molecular cages held together by coordination bonds.


A team headed by Chrys Wesdemiotis and George R. Newkome has now successfully produced an approximately 6 nm cuboctahedron out of organic molecules and metal ions. A cuboctahedron has a surface made of 8 triangles and 6 squares. The conceptual starting point was an X-shaped, organic building block, which, laid over the surface of a cuboctahedron, would give the correct angles between the edges, 60° and 90°. It should also be able to bind metal ions to hold everything together.


Using 12 of these tailored X-shaped terpyridine ligands and 24 metal ions (zinc or cadmium), the researchers were able to make cuboctahedra that self-assembled from the individual building blocks. The team from the University of Akron, the University of Chicago (Argonne), the University of South Florida (Tampa), Florida Atlantic University (Boca Raton), the University of Tokyo (Japan), and the Tianjin University of Technology (China) used a variety of spectroscopic techniques, model calculations, and single-crystal analyses with synchrotron X-ray diffraction to verify the structure. They were even able to see the shapes of the individual molecules with an electron microscope.


One new feature they observed was that the cuboctahedra split apart into two octahedra when the concentration is reduced. If the solution concentration is then increased, the octahedra fuse back together into cuboctahedra. This process could also be initiated by switching between different counterions. This new process could allow for the production of a new series of nanoscale building blocks for the materials sciences. In addition, the zinc cuboctahedra may be suitable for use as transport systems for drugs.

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Gaseous C60 Carbon Buckyballs May Be Ubiquitous in Space

Gaseous C60 Carbon Buckyballs May Be Ubiquitous in Space | Amazing Science | Scoop.it
"Buckyball" molecules appear to be commonplace across the universe, and may even be sources of organic molecules that are key to the origin and evolution of life, a new study suggests.


Nearly 100 years ago, astronomers began spotting unknown absorption bands associated with the  interstellar gas and dust of the Milky Way and other galaxies. More than 400 of these "diffuse interstellar bands" have been found to date, and their cause is "often cited as the biggest enigma of observational astronomy," study co-author John Maier, a spectroscopist and chemical physicist at the University of Basel in Switzerland, told Space.com.


In 1994, researchers suggested that some of these absorption bands might arise from buckyballs, which are cagelike spheres also known as C60, since each molecule is made up of 60 carbon atoms. 

Buckyballs, also known as fullerenes, are named after their resemblance to the architect Buckminster Fuller's geodesic domes, a giant example of which is found at the entrance to Disney World's Epcot theme park in Florida. Discovered in 1985, buckyballs are about 1 nanometer in size, or about one ten-thousandth the average diameter of a human hair.


Five years ago, scientists confirmed that buckyballs exist in space around stars. Now, Maier and his colleagues have found the first unambiguous evidence that buckyballs exist in the interstellar medium between stars in the Milky Way. 


In the lab, the researchers created a positively charged version of C60 known as C60+, which can form when buckyballs are bombarded with radiation. They cooled a gas of C60+ to the kind of temperatures found in deep space — about minus 449 degrees Fahrenheit (minus 267 degrees Celsius). They next tested what C60+'s absorption bands were. Altogether, this project took 20 years, Maier said.


The researchers found that buckyballs are responsible for two diffuse interstellar bands, marking the first time investigators have identified a culprit behind any of these mysterious features. "The whole mystery has not been solved, but perhaps this is the beginning," Maier said.


Previous research suggested buckyballs are created in dying stars and pushed out into planetary nebulas. These new findings suggest buckyballs ultimately make their way into diffuse clouds that provide the seeds for the formation of new stars. "C60+ may well be ubiquitous in space and stable in very hostile environments," Maier said. "Buckyballs may even be the precursors of important organic molecules necessary for the formation of life on planets."


Future research can investigate whether other diffuse interstellar bands are caused by buckyballs laced with metals and other elements, Maier said. The scientists detailed their findings in online Wednesday (July 15) in the journal Nature.

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