Dislocations in oxides such as cerium dioxide, a solid electrolyte for fuel cells, turn out to have a property that is the opposite of what researchers had expected, according to a new analysis. Researchers had thought that a certain kind of strain would speed the transport of oxygen ions through the material, potentially leading to the much faster diffusion that is necessary in high-performance solid-oxide fuel cells.
A research partnership is reporting advances on how to make solar cells stronger, lighter, more flexible and less expensive when compared with the current silicon or germanium technology on the market. The researchers discovered how a blend of conjugated polymers resulted in structural and electronic changes that increased efficiency three-fold, by incorporating graphene in the active layer of the carbon-based materials.
Regulating comfort in small commercial buildings could become more efficient and less expensive thanks to an innovative low-cost wireless sensor technology being developed by researchers at Oak Ridge National Laboratory. Buildings are responsible for about 40% of the energy consumed in the U.S. Studies indicate that advanced sensors and controls have the potential to reduce the energy consumption of buildings by 20 to 30%.
Graphene nanoribbons formed into a 3-D aerogel and enhanced with boron and nitrogen are excellent catalysts for fuel cells, even in comparison to platinum, according to Rice Univ. researchers. A team led by materials scientist Pulickel Ajayan and chemist James Tour made metal-free aerogels from graphene nanoribbons and various levels of boron and nitrogen to test their electrochemical properties.
On the search for high-performance materials for applications such as gas storage, thermal insulators or dynamic nanosystems it’s essential to understand the thermal behavior of matter down to the molecular level. Classical thermodynamics average over time and over a large number of molecules. Within a 3-D space single molecules can adopt an almost infinite number of states, making the assessment of individual species nearly impossible.
Lithium-ion batteries unleash electricity as electrochemical reactions spread through active materials. Manipulating this complex process and driving the reactions into the energy-rich heart of each part of these active materials is crucial to optimizing the power output and ultimate energy capacity of these batteries. Now, scientists have mapped these atomic-scale reaction pathways and linked them to the battery’s rate of discharge.
In science, it’s commonly known that materials can change in a number of ways when subjected to different temperatures, pressures or other environmental forces. A material might melt or snap in half. And for engineers, knowing when and why that might happen is crucial information. Now, a Florida State Univ. researcher has laid out an overarching theory that explains why certain materials act the way they do.
Wake up in the morning and stretch; your midsection narrows. Pull on a piece of plastic at separate ends; it becomes thinner. So does a rubber band. One might assume that when a force is applied along an axis, materials will always stretch and become thinner. Wrong.
The blue-rayed limpet is a tiny mollusk that lives in kelp beds along the coasts of Norway, Iceland, the U.K., Portugal and the Canary Islands. These diminutive organisms might escape notice entirely, if not for a very conspicuous feature: bright blue dotted lines that run in parallel along the length of their translucent shells. Depending on the angle at which light hits, a limpet’s shell can flash brilliantly even in murky water.
A superconductor that works at room temperature was long thought impossible, but scientists at the Univ. of Southern California may have discovered a family of materials that could make it reality. The team found that aluminum "superatoms" appear to form Cooper pairs of electrons at temperatures around 100 K. Though 100 K is still pretty chilly, this is an increase compared to bulk aluminum metal.
Delivering the capability to image nanostructures and chemical reactions down to nanometer resolution requires a new class of x-ray microscope that can perform precision microscopy experiments using ultra-bright x-rays from the National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory.
Massachusetts Institute of Technology researchers have devised a new way to make complex liquid mixtures, known as emulsions, that could have many applications in drug delivery, sensing, cleaning up pollutants and performing chemical reactions. Many drugs, vaccines, cosmetics and lotions are emulsions, in which tiny droplets of one liquid are suspended in another liquid.
Designing or exploring new materials is all about controlling their properties. In a new study, Cornell Univ. scientists offer insight on how different “knobs” can change material properties in ways that were previously unexplored or misunderstood.
To power a car so it can travel hundreds of miles at a time, lithium-ion batteries of the future are going to have to hold more energy without growing too big in size. That's one of the dilemmas confronting efforts to power cars through rechargeable battery technologies. In order to hold enough energy to enable a car trip of 300 to 500 miles before recharging, current lithium-ion batteries become too big or too expensive.
Univ. of Manchester scientists have used graphene to target and neutralize cancer stem cells while not harming other cells. This new development opens up the possibility of preventing or treating a broad range of cancers, using a non-toxic material.
Newly developed tiny antennas, likened to spotlights on the nanoscale, offer the potential to measure food safety, identify pollutants in the air and even quickly diagnose and treat cancer. The new antennas are cubic in shape. They do a better job than previous spherical ones at directing an ultra-narrow beam of light where it is needed, with little or no loss due to heating and scattering.
Superconductor materials are prized for their ability to carry an electric current without resistance, but this valuable trait can be crippled or lost when electrons swirl into tiny tornado-like formations called vortices. These disruptive mini-twisters often form in the presence of magnetic fields, such as those produced by electric motors.
Researchers at McGill Univ. have developed a new, low-cost method to build DNA nanotubes block-by-block, a breakthrough that could help pave the way for scaffolds made from DNA strands to be used in applications such as optical and electronic devices or smart drug delivery systems. Many researchers, including the McGill team, have previously constructed nanotubes using a method that relies on spontaneous assembly of DNA in solution.
Using ultracold atoms as a stand-in for electrons, a Rice Univ.-based team of physicists has simulated superconducting materials and made headway on a problem that's vexed physicists for nearly three decades. The research was carried out by an international team of experimental and theoretical physicists and appears online in Nature. The work could open up a new realm of unexplored science.
Paving the way for lighter and more flexible solar devices, Univ. of California, Los Angeles researchers have identified the key principles for developing high-efficiency polymer solar cells. Today’s commercially produced solar panels use silicon cells to efficiently convert sunlight to energy. But silicon panels are too heavy to be used for energy-producing coatings for buildings and cars, or flexible and portable power supplies.
Univ. of Tokyo researchers have developed a novel selective catalyst that allows the creation of several basic chemicals from biomass instead of petroleum. This discovery may lead to the use of plant biomass as a basic feedstock for the chemical industry. The new catalyst enables selective cleaving (hydrogenolysis) of carbon-oxygen (C-O) single bonds in phenols and aryl methyl ethers, two of the main components of lignin.
Graphene shows great promise for future electronics, advanced solar cells, protective coatings and other uses, and combining it with other materials could extend its range even further. Experiments at the SLAC National Accelerator Laboratory looked at the properties of materials that combine graphene with a common type of semiconducting polymer.
Scientists have known how to draw thin fibers from bulk materials for decades. But a new approach to that old method, developed by researchers at Massachusetts Institute of Technology, could lead to a whole new way of making high-quality fiber-based electronic devices. The idea grew out of a long-term research effort to develop multifunctional fibers that incorporate different materials into a single long functional strand.
Graphene is often touted as a replacement for silicon in electronic devices due to its extremely high conductivity and unbeatable thinness. But graphene isn’t the only 2-D material that could play such a role. Univ. of Pennsylvania researchers have made an advance in manufacturing one such material, molybdenum disulphide.
Most lenses are, by definition, curved. After all, they are named for their resemblance to lentils, and a glass lens made flat is just a window with no special powers. But a new type of lens created at the Harvard School of Engineering and Applied Sciences turns conventional optics on its head.