Although most materials slightly expand when heated, there is a new class of rubber-like material that not only self-stretches upon cooling; it reverts back to its original shape when heated, all without physical manipulation. The material is like a shape-memory polymer because it can be switched between two different shapes.
As you heat up a piece of iron, the arrangement of the iron atoms changes several times before melting. This unusual behavior is one reason why steel, in which iron plays a starring role, is so sturdy and ubiquitous in everything from teapots to skyscrapers. But the details of just how and why iron takes on so many different forms have remained a mystery.
With a low price tag and mild flavor, tilapia has become a staple dinnertime fish for many Americans. Now it could have another use: helping to heal our wounds. In ACS Applied Materials & Interfaces, scientists have shown that a protein found in this fish can promote skin repair in rats without an immune reaction, suggesting possible future use for human patients.
Researchers from North Carolina State Univ. are using a technique they developed to observe minute distortions in the atomic structure of complex materials, shedding light on what causes these distortions and opening the door to studies on how such atomic-scale variations can influence a material's properties.
Scientists used supercomputers to find a new class of materials that possess an exotic state of matter known as the quantum spin Hall effect. The researchers published their results in Science in December 2014, where they propose a new type of transistor made from these materials. The team calculated the electronic structures of the materials using the Stampede and Lonestar supercomputers of the Texas Advanced Computing Center.
More than 80% of microbial infections in the human body are caused by a build–up of bacteria, according to the National Institutes of Health. Bacteria cells gain a foothold in the body by accumulating and forming into adhesive colonies called biofilms, which help them to thrive and survive but cause infections and associated life–threatening risks to their human hosts.
How do you make nickel look and behave like copper? A team of scientists at Yale Univ. has done just that by developing a novel technique to artificially alter a material’s atomic properties by substantially modifying the orbital properties of electrons. The electrons can also be tunably configured in orbital patterns with unique magnetic, superconductive and optical properties.
Treated buckyballs not only remove valuable but potentially toxic metal particles from water and other liquids, but also reserve them for future use, according to scientists at Rice Univ. The Rice lab of chemist Andrew Barron has discovered that carbon-60 fullerenes (buckyballs) that have gone through the chemical process known as hydroxylation aggregate into pearl-like strings as they bind to and separate metals from solutions.
Metamaterials offer tantalizing future prospects such as high-resolution optical microscopes and superfast optical computers. To realize the vast potential of metamaterials, however, scientists will need to hone their understanding of the fundamental physics behind them. This will require accurately predicting nonlinear optical properties.
Injectable nanoparticles that could protect an injured person from further damage due to oxidative stress have proven to be astoundingly effective in tests to study their mechanism. A team of scientists designed methods to validate their 2012 discovery that combined polyethylene glycol-hydrophilic carbon clusters could quickly stem the process of overoxidation that can cause damage in the minutes and hours after an injury.
Artists, print designers and interior decorators have long had access to a broad palette of paint and ink colors for their work. Now, researchers have created a broad color palette of electrochromic polymers, materials that can be used for sunglasses, window tinting and other applications that rely on electrical current to produce color changes.
A team of Caltech chemists has discovered a method for producing a group of silicon-containing organic chemicals without relying on expensive precious metal catalysts. Instead, the new technique uses as a catalyst a cheap, abundant chemical that is commonly found in chemistry labs around the world, potassium tert-butoxide, to help create a host of products ranging from new medicines to advanced materials.
When a metal tube lines an oil well thousands of feet below the surface of the ocean, that metal had better be solid and reliable. Unfortunately, the environment in such deep wells is often rich in hydrogen, a gas that can penetrate high-tech alloys and make them brittle, making fractures and leaks more likely. Now researchers have figured which characteristics of a metal structure foster this embrittlement in the presence of hydrogen.
While the mysterious, unseen forces magnets project are now (mostly) well understood, they can still occasionally surprise us. For instance, thin films of cobalt have been observed to spontaneously switch their poles: something that typically doesn’t happen in the absence of an external magnetic field. Physicists at NIST and the Univ. of Maryland have measured this phenomenon on the largest scale yet.
Researchers at Virginia Commonwealth Univ. and universities in China and Japan have discovered a new structural variant of carbon called "penta-graphene", a very thin sheet of pure carbon that has a unique structure inspired by a pentagonal pattern of tiles found paving the streets of Cairo.
Far from being a defect, a winding thread of odd rings at the border of two sheets of graphene has qualities that may prove valuable to manufacturers, according to Rice Univ. scientists. Graphene rarely appears as a perfect lattice of chicken wire-like six-atom rings. When grown via chemical vapor deposition, it usually consists of “domains,” or separately grown sheets that bloom outward from hot catalysts until they meet up.
The editors of R&D Magazine are looking for speakers to participate in a webinar on “Using Multiple Materials in 3D Printing.” Candidates are asked to give a 15-min PowerPoint-based talk over the phone on their experiences in fabricating 3D printed products using multiple materials or developing the processes and/or technologies to accomplish this.
Efficiency is big in the tiny world of thermoelectric nanowires. Researchers at Sandia National Laboratories say better materials and manufacturing techniques for the nanowires could allow carmakers to harvest power from the heat wasted by exhaust systems or lead to more efficient devices to cool computer chips.
If you can’t find the ideal material, then design a new one. Northwestern Univ.’s James Rondinelli uses quantum mechanical calculations to predict and design the properties of new materials by working at the atom-level. His group’s latest achievement is the discovery of a novel way to control the electronic band gap in complex oxide materials without changing the material’s overall composition.
Engineers are shining new light on an emerging family of solar-absorbing materials that could clear the way for cheaper and more efficient solar panels and LEDs. The materials, called perovskites, are particularly good at absorbing visible light, but had never been studied in their purest form: as perfect single crystals.
Imagine eyeglasses that can go quickly from clear to shaded and back again when you want them to, rather than passively in response to changes in light. Scientists report a major step toward that goal, which could benefit pilots, security guards and others who need such control, in ACS Applied Materials & Interfaces.
In Science, Los Alamos National Laboratory researchers reveal a new solution-based hot-casting technique that allows growth of highly efficient and reproducible solar cells from large-area perovskite crystals. The researchers fabricated planar solar cells from pervoskite materials with large crystalline grains that had efficiencies approaching 18%.
A potential avenue to quantum computing currently generating quite the buzz in the high-tech industry is “valleytronics,” in which information is coded based on the wavelike motion of electrons moving through certain 2-D semiconductors. Now, a promising new pathway to valleytronic technology has been uncovered by researchers with the Lawrence Berkeley National Laboratory.
Friction impacts motion, hence the need to control friction forces. Currently, this is accomplished by mechanistic means or lubrication, but experiments conducted by researchers at Oak Ridge National Laboratory have uncovered a way of controlling friction on ionic surfaces at the nanoscale using electrical stimulation and ambient water vapor.
Nature packs away carbon in chalk, shells and rocks made by marine organisms that crystallize calcium carbonate. Now, research suggests that the soft, organic scaffolds in which such crystals form guide crystallization by soaking up the calcium like an "ion sponge". Understanding the process better may help researchers develop advanced materials for energy and environmental uses, such as for removing carbon dioxide from the atmosphere.