Iron carbonyl complexes are used in a large number of chemical reactions and industrial processes, but until recently, it has not been possible to apply these studies in homogeneous catalysis which take place in solution. Scientists have now combined the spectroscopic method called resonant inelastic x-ray scattering with so-called ab initio theory in order to describe these processes in detail.
The smallest unit of a magnet is the magnetic moment of a single atom or ion. Researchers in Germany wanted to find out whether the magnetism of a pair of magnetic moments can be measured electrically in a single molecule. To do this, they succeeded in performing an extraordinary experiment which shows how magnetism that generally manifests itself by a force between two magnetized objects acts within a single molecule.
Researchers from North Carolina State Univ. have developed more accurate measurements of how efficiently a polymer called MEH-PPV amplifies light, which should advance efforts to develop a new generation of lasers and photonic devices. MEH-PPV is a low-cost polymer that can be integrated with silicon chips, and researchers have sought to use the material to convert electricity into laser light for use in photonic devices.
Researchers in California have demonstrated that indium phosphide, a III-V compound, can be grown on thin sheets of metal foil in a process that is faster and cheaper than traditional methods, yet still comparable in optoelectronic characteristics. Indium phosphide is among the high-performance solar converter, but has been up to 10 times as expensive as silicon to integrate in photovoltaic cells.
Thin glass is already widely used for displays. But even thinner glass, about one-tenth the thickness of display glass, can be customized to store energy at high temperatures. Recent experiments by a partnership of academic and industrial researchers have investigated various alkali-free glass compositions and thicknesses, and has resulted in inexpensive roll-to-roll glass capacitors with high energy density and high reliability.
Fixation processes free up nitrogen atoms from their diatomic form, but nitrogen does not easily react with other chemicals to form new compounds. Researchers in South Korea have invented a simple and eco-friendly method of creating nitrogen-doped graphene nanoplatelets that simultaneously facilitates the nitrogen-fixation process and creates useful tools for building dye-sensitized solar cells and fuel cells.
The principle of proton conduction in water has been known for 200 years and is named after its discoverer, Theodor Grotthuss. Using theoretical calculations, researchers have now been able to analyze this mechanism in more detail and have shown that the currently accepted picture of proton diffusion, which has been compared to a “bucket line”, may need to be revised.
An international collaboration has fabricated a self-assembled nanofiber from a DNA building block that contains both duplex and quadruplex DNA. This work is a first step toward the creation of new structurally heterogeneous, yet controllable, DNA-based materials exhibiting novel properties suitable for bottom-to-top self-assembly for nanofabrication.
Unlike barnacles, which cement themselves tightly to surfaces, mussels dangle more loosely from these surfaces, attached by a collection of fine filaments known as byssus threads. This approach lets the creatures drift further out into the water, where they can absorb nutrients. Despite the fragile appearance of these threads, they can withstand impact forces that are nine times greater than forces exerted by stretching in one direction.
Diffusion of sodium ions from the glass substrate is thought to be the primary cause of potential-induced degradation (PID) in crystalline silicon photovoltaic cells. A research institute and metals company in Japan have partnered to develop a thin film solution. The titanium oxide-based composite metal compound they have developed is inexpensive to produce and highly scalable.
The properties of nanomaterials could be easier to predict in the future thanks to work by researchers who have studied metal they have ground metal continuously finer powders. They have prepared a detailed catalogue of how the structure of the metal grains changes depending on grain size, and have discovered that the crystal lattices initially shrink, but expand again below a certain threshold grain size.
Catalysts are everywhere. They make chemical reactions that normally occur at extremely high temperatures and pressures possible within factories, cars and the comparatively balmy conditions within the human body. Developing better catalysts, however, is mainly a hit-or-miss process. Now, researchers have shown a way to precisely design the active elements of a certain class of catalysts.
Concentric hexagons of graphene grown in a furnace at Rice University represent the first time anyone has synthesized graphene nanoribbons on metal from the bottom up—atom by atom. As seen under a microscope, the layers brought onions to mind. Though flat graphene could never be like an onion, the name stuck.
If you squeeze a normal object in all directions, it shrinks in all directions. But a few strange materials will actually grow in one dimension when compressed. A team of chemists has now discovered a structure that takes this property to a new level, expanding more dramatically under pressure than any other known material.
Catalysts are everywhere, but developing better catalysts is mainly a hit-or-miss process. Now, a study by researchers at the University of Pennsylvania, the University of Trieste, Italy, and Brookhaven National Laboratory has shown a way to precisely design the active elements of a certain class of catalysts, showing which parameters are most critical for improving performance.
Antennas that are capable of transmitting radio waves turn components into intelligent objects. Researchers in Germany have now found a way to embed these antennas in fiber composites. As a result, the technology also works with carbon and glass fibers.
Butterfly wings can do remarkable things with light, and humans are still trying to learn from them. Physicists have now uncovered how subtle differences in the tiny crystals of butterfly wings create stunningly varied patterns of color even among closely related species. The discovery could lead to new coatings for manufactured materials that could change color by design.
Researchers from NIST and the Univ. of Maryland have shown how to make nanoscale measurements of critical properties of plasmonic nanomaterials—the specially engineered nanostructures that modify the interaction of light and matter for a variety of applications. Their technique is one of the few that allows researchers to make actual physical measurements of these materials at the nanoscale without affecting the nanomaterial's function.
A team led by John Hagopian, an optics engineer at NASA’s Goddard Space Flight Center, has recently demonstrated that it can grow a uniform layer of carbon nanotubes through the use of atomic layer deposition. The marriage of the two technologies now means that NASA can grow nanotubes on 3-D components, such as complex baffles and tubes commonly used in optical instruments.
Researchers have developed a drug delivery technique for diabetes treatment in which a sponge-like material surrounds an insulin core. The sponge expands and contracts in response to blood sugar levels to release insulin as needed. The technique could also be used for targeted drug delivery to cancer cells.
More than a decade ago, two researchers uncovered a counter-intuitive property of zeolites. When they put these porous minerals in water, and then put the water under high pressure, the tiny cavities within the zeolites actually grew in size. Recent x-ray diffraction studies by the team have revealed the interior geometry of the cavities and the arrangement of the cations and water molecules held within, before and after pressurization.
Until now, polymers with temperature-controlled shape memory could only change form once. Biomaterial researchers have recently developed plastics that can repeatedly change from one shape to another and then back again when temperatures fluctuate within a selected range. The material is dubbed “polymer actuators” by its creators in Germany.
A team of Massachusetts Institute of Technology researchers has carried out the first systematic investigation of the factors that control boiling heat transfer from a surface to a liquid. This process is crucial to the efficiency of power plants and the cooling of high-power electronics, and could even lead to improvements in how vehicles travel through water.
Using carpets of aligned carbon nanotubes, researchers from Rice University and Sandia National Laboratories have created a solid-state electronic device that is hardwired to detect polarized light across a broad swath of the visible and infrared spectrum.
The Air Force Office of Scientific Research has been working with Jim Tour’s laboratory at Rice University to make graphene suitable for a variety of organic chemistry applications. Recently, the partnership made another technological advance. Their work has shown that graphene nanoribbons can significantly increase the storage capacity of lithium ion by combining these 2D ribbons with tin oxide.