Evolution of a bimetallic nanocatalyst

Atomic-scale snapshots of a bimetallic nanoparticle catalyst in action have provided insights that could help improve the industrial process by which fuels and chemicals are synthesized from natural gas, coal or plant biomass. A multi-national lab collaboration led by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has taken the most detailed look ever at the evolution of platinum/cobalt bimetallic nanoparticles during reactions in oxygen and hydrogen gases. 

 

TEM image of platinum/cobalt bimetallic nanoparticle catalyst in action shows that during the oxidation reaction, cobalt atoms migrate to the surface of the particle, forming a cobalt oxide epitaxial film, like water on oil.

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Fighting cancer with lasers and nanoballoons that pop

Chemotherapeutic drugs excel at fighting cancer, but they’re not so efficient at getting where they need to go.

They often interact with blood, bone marrow and other healthy bodily systems. This dilutes the drugs and causes unwanted side effects.

Now, researchers are developing a better delivery method by encapsulating the drugs in nanoballoons – which are tiny modified liposomes that, upon being struck by a red laser, pop open and deliver concentrated doses of medicine.

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The image shows a nanoballoon before (left) and after (right) being hit by a red laser. The laser causes the balloon to pop open and release the anti-cancer drugs directly at a tumor. Credit: Jonathan Lovell

Making the Most of Carbon Nanotube-Liquid Crystal Combos

Dispersions of carbon nanotubes with liquid crystals have attracted much interest because they pave the way for creating new materials with added functionalities. 

Now, a study published in EPJ E by Marina Yakemseva and colleagues at the Nanomaterials Research Institute in Ivanovo, Russia, focuses on the influence of temperature and nanotube concentration on the physical properties of such combined materials. 

These findings could have implications for optimising these combinations for non-display applications, such as sensors or externally stimulated switches, and novel materials that are responsive to electric, magnetic, mechanical or even optical fields.

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Dispersed multi-wall carbon nanotubes on a glass surface. Credit: Yakemseva et al.

Nanotube Coating Helps Shrink Mass Spectrometers

Nanotube coating helps shrink mass spectrometers

Nanotechnology is advancing tools likened to Star Trek's "tricorder" that perform on-the-spot chemical analysis for a range of applications including medical testing, explosives detection and food safety.

Researchers found that when paper used to collect a sample was coated with carbon nanotubes, the voltage required was 1,000 times reduced, the signal was sharpened and the equipment was able to capture far more delicate molecules.

A carbon nanotube-coated paper triangle placed on an ionization source charged by a small battery is held in front of a mass spectrometer. Researchers at Purdue University and the Indian Institute of Technology Madras studied the use of carbon nanotubes to advance ambient ionization techniques. (Purdue University photo/Courtesy of Thalappil Pradeep)

Toward ‘Vanishing’ Electronics and Unlocking Nanomaterials’ Power Potential

Brain sensors and electronic tags that dissolve. Boosting the potential of renewable energy sources. These are examples of the latest research from two pioneering scientists selected as this year’s Kavli lecturers at the 247^th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society.

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Biodegradable materials from Rogers’ lab could one day transform electronics for consumer and medical devices, as illustrated here in a dissolvable RFID tag prototype.

Credit: John Rogers

Microparticles Show Molecules Their Way

A team of researchers of Karlsruhe Institute of Technology (KIT) and the University of Michigan/USA has produced novel microparticles, whose surface consists of three chemically different segments. 

These segments can be provided with different (bio-) molecules. 

Thanks to the specific spatial orientation of the attached molecules, the microparticles are suited for innovative applications in medicine, biochemistry, and engineering. 

The researchers now report about their development in the journal “Angewandte Chemie“.

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The small, but highly complex particles contain chemically different segments. (Photo: Angewandte Chemie)

ORNL microscopy system delivers real-time view of battery electrochemistry | ornl.gov

Using a new microscopy method, researchers at the Department of Energy’s Oak Ridge National Laboratory can image and measure electrochemical processes in batteries in real time and at nanoscale resolution.

Scientists at ORNL used a miniature electrochemical liquid cell that is placed in a transmission electron microscope to study an enigmatic phenomenon in lithium-ion batteries called the solid electrolyte interphase, or SEI, as described in a study published in Chemical Communications.

Read more at ORNL Microscopy System Delivers Real-time View of Battery Electrochemistry | ornl.gov

A new in situ transmission electron microscopy technique enabled ORNL researchers to image the snowflake-like growth of the solid electrolyte interphase from a working battery electrode.

 

Caps Not the Culprit in Nanotube Chirality

A single-walled carbon nanotube grows from the round cap down, so it’s logical to think the cap’s formation determines what follows. But according to researchers at Rice University, that’s not entirely so.

Theoretical physicist Boris Yakobson and his Rice colleagues found through exhaustive analysis that those who wish to control the chirality of nanotubes – the characteristic that determines their electrical properties – would be wise to look at other aspects of their growth.

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Carbon nanotube caps are forced into shape by six pentagons among the array of hexagons in the single-atom-thick tube. Rice University researchers took a census of thousands of possible caps and found the energies dedicated to their formation have no bearing on the tube’s ultimate chirality. (Credit: Evgeni Penev/Rice University) - 

Leeds Researchers Build World’s Most Powerful Terahertz Laser Chip

University of Leeds researchers have taken the lead in the race to build the world’s most powerful terahertz laser chip. 

 

A paper in the Institution of Engineering and Technology’s (IET) journal Electronics Letters reports that the Leeds team has exceeded a 1 Watt output power from a quantum cascade terahertz laser.

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Credit: University of Leeds

Putting the Power in Power-Dressing

Scientists in the UK developing wearable electronics have knitted a flexible fabric that delivers twice the power output of current energy harvesting textiles.

There is considerable interest and research into wearable piezoelectric energy harvesters that use waste energy from human movement or the ambient environment to power low-energy consuming wearable devices, such as wireless sensors and consumer electronics.

 

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The fabric is composed of two separate conducting, silver-coated polyamide textile faces joined together by a PVDF spacer yarn. Credit: Navneet Soin et al.

Rice’s Carbon Nanotube Fibers Outperform Copper

On a pound-per-pound basis, carbon nanotube-based fibers invented at Rice University have greater capacity to carry electrical current than copper cables of the same mass, according to new research.

While individual nanotubes are capable of transmitting nearly 1,000 times more current than copper, the same tubes coalesced into a fiber using other technologies fail long before reaching that capacity.

But a series of tests at Rice showed the wet-spun carbon nanotube fiber still handily beat copper, carrying up to four times as much current as a copper wire of the same mass.

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Scanning electron microscope images show typical carbon nanotube fibers created at Rice University and broken into two by high-current-induced Joule heating. Rice researchers broke the fibers in different conditions – air, argon, nitrogen and a vacuum – to see how well they handled high current. The fibers proved overall to be better at carrying electrical current than copper cables of the same mass. (Credit: Kono Lab/Rice University

New Understanding Could Result in More Efficient Organic Solar Cells

The goal of making cheap organic solar cells may have gotten a little more approachable with a new understanding of the basic science of charge separation presented in a paper published online today, February 3, in Nature Communications. 

Co-authored by Penn State electrical engineer Noel Giebink with lead author Bethany Bernardo, an undergraduate in his group, and colleagues at IMEC in Belgium, Argonne National Lab, Northwestern, and Princeton, the paper suggests design rules for making more efficient solar cells in the future.

Organic solar cells currently have a top efficiency of approximately 10 percent in the laboratory, much less than inorganic single crystal silicon. 

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An electron wave function, indicated by orange shading, spreads across several nanocrystalline fullerene molecules in this representation of an organic solar cell heterojunction. Image Credit: Giebink, Penn State

 

Molecular Traffic Jam Makes Water Move Faster through Nanochannels

Seth Lichter

Cars inch forward slowly in traffic jams, but molecules, when jammed up, can move extremely fast.

New research by Northwestern University researchers finds that water molecules traveling through tiny carbon nanotube pipes do not flow continuously but rather intermittently, like stop-and-go traffic, with unexpected results.

“Previous molecular dynamics simulations suggested that water molecules coursing through carbon nanotubes are evenly spaced and move in lockstep with one another,” said Seth Lichter, professor of mechanical engineering at Northwestern’s McCormick School of Engineering and Applied Science.

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Gold and Silica Nanostars Imitate the Two Faces of the God Janus

Researchers from the Basque centre CIC biomaGUNE and the University of Antwerp (Belgium) have designed nanoparticles with one half formed of gold branches and the other of silicon oxide. 

They are a kind of Janus particle, so-called in honour of the Roman god with two faces, which could be used in phototherapy in the future to treat tumours.

In Roman mythology, Janus was the god of gates, doors, beginnings and transitions between the past and the future. In fact, the first month of the year, January (from the Latin, ianuarĭus), bears his name. 

This deity was characterised by his profile of two faces, something which has inspired scientists, when naming their chemical designs with two clearly distinct components.

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Two examples of nanostars with one silicon oxide face (bluish) and another with golden branches (yellow). / Credit: Liz-Marzán et al.

Making a Gem of a Tiny Crystal: Slowly Cooled DNA Transforms Disordered Nanoparticles Into Orderly Crystal

Nature builds flawless diamonds, sapphires and other gems. Now a Northwestern University research team is the first to build near-perfect single crystals out of nanoparticles and DNA, using the same structure favored by nature.

"Single crystals are the backbone of many things we rely on -- diamonds for beauty as well as industrial applications, sapphires for lasers and silicon for electronics," said nanoscientist Chad A. Mirkin. "The precise placement of atoms within a well-defined lattice defines these high-quality crystals. 

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Cut diamond. Nature builds flawless diamonds, sapphires and other gems. Now a Northwestern University research team is the first to build near-perfect single crystals out of nanoparticles and DNA, using the same structure favored by nature. (Credit: © tiero / Fotolia)

Credit: Northwestern University research team

Water Glides Freely Across 'Nanodrapes' Made from the World's Thinnest Material

Engineering researchers at Rensselaer Polytechnic Institute have developed a new drape made from graphene—the thinnest material known to science—which can enhance the water-resistant properties of materials with rough surfaces. These “nanodrapes” are less than a nanometer thick, chemically inert, and provide a layer of protection without changing the properties of the underlying material. The team of researchers, led by Rensselaer Professor Nikhil Koratkar, demonstrated how droplets of water encounter significantly less friction when moving across a surface covered with a nanodrape. - 

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Engineering researchers have developed a new drape made from graphene —- the thinnest material known to science —- which can enhance the water-resistant properties of materials with rough surfaces. (Credit: RPI)

Credit: Rensselaer Polytechnique Institute

Rensselaer

Wagon-Wheel Pasta Shape for Better LED Lights

One problem in developing more efficient organic LED light bulbs and displays for TVs and phones is that much of the light is polarized in one direction and thus trapped within the light-emitting diode, or LED. University of Utah physicists believe they have solved the problem by creating a new organic molecule that is shaped like rotelle – wagon-wheel pasta – rather than spaghetti.

The rotelle-shaped molecule – known as a “pi-conjugated spoked-wheel macrocycle” – acts the opposite of polarizing sunglasses, which screen out glare reflected off water and other surfaces and allow only direct sunlight to enter the eyes.

Images of molecules for light-emitting diodes on the left are compared with similar shaped pasta on the right. The upper left electron microscope image shows spaghetti-shaped organic polymers now used for organic light-emitting diodes, or OLEDs. The lower left image shows new molecules -- created by scientists at the University of Utah and two German universities -- that are shaped like wagon-wheel or rotelle pasta and emit light more efficiently than the spaghetti-shape polymers. (Credit: Molecule images by Stefan Jester, University of Bonn. Pasta images courtesy Wikimedia Commons. Wagon wheel pasta image has been released into the public domain by its author, Fazalmajid at the English project. Spaghetti image has been licensed under the Creative Commons Attribution-Share Alike 2.0 Generic license)

 Credit: University of Utah

SU Chemists Develop 'Fresh, New' Approach to Making Alloy Nanomaterials

Chemists in The College of Arts and Sciences have figured out how to synthesize nanomaterials with stainless steel-like interfaces. Their discovery may change how the form and structure of nanomaterials are manipulated, particularly those used for gas storage, heterogeneous catalysis and lithium-ion batteries.

Until now, scientists have used many wet-chemical approaches—collectively known as colloidal synthesis—to manipulate reactions in which metallic ions form alloys at the nanoscale. Here, metal nanoparticles are typically 2 to 50 nanometers in size and have highly unique properties, including various colors, high reactivity and novel chemistry.

Associate Professor Mathew M. Maye, right, with research assistant Wenjie Wu G’11, G’13 (Credit: Image courtesy of Syracuse University)

Credit: Syracuse University

Molecules Form 2-D Patterns Never Before Observed: Nanoscience Experiments Produce Elusive 5-Vertex Tilings

Tessellation patterns that have fascinated mathematicians since Johannes Kepler worked out their systematics 400 years ago – and that more recently have caught the eye of both artists and crystallographers – can now be seen in the laboratory. 

They first took shape on a surface more perfectly two-dimensional than any sheet of writing paper, a single layer of atoms and molecules atop an atomically smooth substrate. 

Physicists coaxed these so-called Kepler tilings "onto the page" through guided self-assembly of nanostructures. The experiments were carried out by postdoctoral researcher David Ecija, PhD candidate Jose Ignacio Urgel and colleagues in the Physics Department of Technische Universitaet Muenchen (TUM), in collaboration with scientists in Karlsruhe and Zurich. They reported their findings in the Proceedings of the National Academy of Sciences.

The 2-D tessellation pattern known as the "semiregular snub square tiling" stands out clearly in this image, which combines scanning tunneling microscopy with computer graphics. The pattern, observed in a surface architecture just one molecule thick, was formed by self-assembly of linear organic linkers, imaged as rods, and lanthanide cerium centers, visualized as bright protrusions. The area shown measures less than 25 nanometers across. (Credit: Barth Lab, copyright TUM)

Credit: http://www.eurekalert.org

Pass the Salt: Common Condiment Could Enable New High-Tech Industry -- Silicon Nanostructures

Chemists at Oregon State University have identified a compound that could significantly reduce the cost and potentially enable the mass commercial production of silicon nanostructures -- materials that have huge potential in everything from electronics to biomedicine and energy storage.

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This silicon nanostructure was created using a new process developed at Oregon State University. (Credit: Image courtesy of Oregon State University)

Credit: http://oregonstate.edu