[Image above] Credit: NIST
Researchers at McMaster University have cleared that obstacle by developing a new way to purify carbon nanotubes. The group reversed the electronic characteristics of a polymer known to disperse semiconducting nanotubes, while leaving the rest of the polymer’s structure intact. By so doing, they have reversed the process, leaving the semiconducting nanotubes behind while making it possible to disperse the metallic nanotubes.
NIST scientists have devised and modeled a unique optical method of sorting microscopic and nanoscopic particles by size, with a resolution as fine as 1 nm for particles of similar composition. A stream of particles of various sizes enters the system at a single point, but the particles exit the system at different places, depending on their size. The sorting operates on a continuous input of particles, with the particles moving through the system in only a couple of seconds.
By combining expertise in photonics—manipulating light beams in nanoscale waveguides on a chip—and materials science, Cornell researchers have laid the groundwork for a chemical sensor on a chip that could be used in small portable devices to analyze samples in a lab, monitor air and water quality in the field and perhaps even detect explosives.
A research team from the Georgia Institute of Technology and ExxonMobil has demonstrated a new carbon-based molecular sieve membrane that could dramatically reduce the energy required to separate a class of hydrocarbon molecules known as alkyl aromatics.
A new paper provides proof of a new concept, using new solid 3D superlenses to break through the scale of things previously visible through a microscope. Illustrating the strength of the new superlens, the scientists describe seeing for the first time, the actual information on the surface of a Blue Ray DVD.
Lithium-ion batteries store a lot of energy in a small space, making them the energy source of choice for mobile electronic devices. Today, mobile phones, laptops, e-bikes and electric cars are all powered by such batteries. Researchers at ETH Zurich have now developed a type of battery that, unlike conventional ones, consists entirely of solid chemical compounds and is non-flammable.
Researchers have revealed a class of materials that could be better at converting sunlight into energy than those currently used in solar arrays. Their findings show how a ferroelectric insulator can extract power from a portion of the sunlight spectrum with conversion efficiency above its theoretical maximum (Shockley-Queisser limit).
SDSU engineering researchers are using biochar, an inexpensive carbon-rich material, and a new method of creating the porous surface needed to capture electricity to reduce the cost of supercapacitors. The charcoal-like biochar can be made from crop residue, such as corn stover, wood or even dried distillers grain with solubles. To do the plasma etching, oxygen was used and excited by radio frequency through a dielectric barrier discharge.
An MIT spinout is preparing to commercialize a novel rechargable lithium metal battery that offers double the energy capacity of the lithium ion batteries that power many of today’s consumer electronics. SolidEnergy Systems has developed an “anode-free” lithium metal battery with several material advances that make it twice as energy-dense, yet safe and long-lasting.
A new study by French and German scientists has attempted to resolve the long-standing debate over the microscopic mechanisms generating the state of matter of glass and whether it is a “real” solid—resulting from a genuine thermodynamic phase transition toward a rigid state—or a hyperviscous liquid without long-range order.
A team from Imperial College London has developed a set of DNA tools to control and engineer a strain of bacteria—normally found in a fermented green tea drink called kombucha tea—to produce modified bacterial cellulose on command. This technique also enables the team to “weave” proteins and other biomolecules into the fabric of the bacterial cellulose as it grows.
Developers of imaging systems have long been beholden to certain rules of optics designs so well established and seemingly immutable as to be treated as virtual “laws” of physics. DARPA’s EXTREME Optics and Imaging program aims to break from well-worn paradigms by introducing engineered optical materials and associated design tools for creating innovative optical systems with improved performance, new functionality, and drastically reduced size and weight.
Researchers have developed an alternative material—hexagonal boron nitride semiconductors—for neutron detection. This material fulfills many key requirements for helium gas detector replacements and can serve as a low-cost alternative in the future.
Cement paste has a large amount of water in its structure, and much of it is confined in the smallest pores of the cement, which are about 1 nm in size. The extreme temperatures in which cement finds itself in certain infrastructures, such as oil wells, lead to changes in water state, which in turn cause internal stresses in the cement. Scientists have characterized the physics of this water in order to contribute towards better cement design.
Physicists have an explanation for why certain materials can conduct electricity without resistance at temperatures well above those required by conventional superconductors. Understanding this exotic behavior may pave the way for engineering materials that become superconducting at room temperature—a capability that could transform the way energy is produced, transmitted, and used.