CTT-other mat stories

CTT-other mat stories

Molecule-thick glass is world’s thinnest, Guinness says

At just a molecule thick, it’s a new record: The world’s thinnest sheet of glass. An accidental discovery by scientists at Cornell University and Germany’s University of Ulm has been recorded for posterity in the Guinness Book of World Records. The research that describes direct imaging of the super-thin glass was published in January 2012 in Nano Letters. Guinness records officials took note and will include the achievement in the latest edition of their book. Just two atoms thick, the glass was formed as the result of an air leak in a reactor during graphene production, scientists believe. Besides its novelty, the work has helped shed light on the fundamental structure of glass and may one day provide a defect-free, ultrathin material for use in future electronics devices.

New ultraviolet LED could lead to portable, low-cost devices

Commercial uses for ultraviolet light are growing, and now a new kind of LED under development at Ohio State University could lead to more portable and low-cost uses of the technology. The patent-pending LED creates a more precise wavelength of UV light than current commercially available UV LEDs, runs at much lower voltages, and is more compact than other methods for creating UV light at precise wavelengths. The LED could lend itself to chemical detection, disinfection, and UV curing applications, and might someday provide a source for UV lasers for eye surgery and computer chip manufacture. Developed using gadolinium-doped semiconductor nanowires, the UV LED operates at around 10 volts.

Airbrushing technique could enable large-scale manufacture of carbon nanofibers

Researchers from North Carolina State University have used airbrushing techniques to grow vertically aligned carbon nanofibers on aluminum, copper, and titanium substrates, according to a news release. The scientists used an airbrush technique to coat metal substrates with nickel nanoparticles that are commonly used as catalysts to grow carbon nanofibers, resulting in a fairly uniform coating that can be quickly applied to large areas at room temperature. After applying the nickel material, the researchers airbrushed the substrate with a layer of silicon powder and heated the coated substrate to 600°C in a reactor filled with acetylene and ammonia gas. Carbon nanofibers formed under the nickel nanoparticles and were held upright by a silicon-enriched coating.

Magnetic ‘sea urchin’ nanoparticles discovered by accident

A nanoparticle shaped like a spiky ball, with magnetic properties, has been discovered by physicists at Queen Mary University of London and the University of Kent who were trying to develop a new method of synthesizing carbon nanotubes. Described as sea urchins because of their characteristic spiny appearance, the particles consist of nanotubes filled with iron, with “spines” of equal length pointing outwards in all directions from a central particle. The presence of iron and the unusual nanoparticle shape could have potential for a number of applications, such as batteries that can be charged from waste heat, mixing with polymers to make permanent magnets, or as particles for cancer therapies that use heat to kill cancerous cells, scientists say.

Graphene-reinforced alumina tougher, more conductive

Graphene can reinforce ceramics while making them conductive, according to scientists at Spain’s Graphenea. The researchers found that graphene additions as small as 0.22 percent made alumina up to 50 percent less likely to break under strain. Other mechanical properties remained about the same as pure alumina, but the material became a hundred million times more electrically conductive. The company says its method is simple, fast, and scalable, and also could be used for reinforcing other ceramic materials such as silicon carbide, silicon nitride, titania, and zirconia.