Chemistry Nexus

by WebElements: the periodic table on the web

The U.S. Department of Energy’s Brookhaven National Laboratory reports that scientists at the US Brookhaven National Laboratory and the IBM T.J. Watson Research Center caused an individual carbon nanotube to emit light for the first time. This may have significance for many of the proposed applications for carbon nanotubes including in electronics and photonics.

The light emission is the result of a process called “electron-hole recombination.” By running an electric current through a carbon nanotube – a long, hollow cylindrical molecule that is only one and a half nanometers (a billionth of a meter) in diameter – negatively charged electrons in the nanotube molecule combine with positively charged “holes,” which are locations in the molecule where electrons are missing.

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December 13th, 2009

Posted In: Chemistry, Nanoscience and nanotechnology

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Nature reports that a new form of carbon was created when physicists at the Australian National University in bombarded a carbon target with a laser. As the carbon reached temperatures of around 10000 °C, it formed an intersecting web of carbon tubes called a ‘nanofoam’. This is said to be a fifth form of carbon known after graphite, diamond, buckminsterfullerenes (buckyballs), and nanotubes.

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December 9th, 2009

Posted In: Chemistry, Nanoscience and nanotechnology

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An egg-shaped fullerene, or “buckyball egg” has been made and characterized by chemists in America at UC Davis (California), Virginia Tech, and Emory and Henry College in Virginia. They were trying to encapsulate terbium atoms within fullerenes but instead encapsulated terbium nitride within an egg-shaped fullerene. [http://dx.doi.org/10.1021/ja063636k]
The compound Tb3N@C84 was synthesized using an arc-discharge generator by vaporizing composite graphite rods containing a mixture of Tb4O7, graphite, and iron nitride as catalyst in a low-pressure He/N2atmosphere.

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August 6th, 2006

Posted In: Chemistry, Crystallography, Nanoscience and nanotechnology

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Workers at The University of Wisconsin-Madison in the USA have managed to release thin membranes of semiconductors from a substrate and transfer them to new surfaces.1

The freed membranes which are just tens of nanometers thick retain all the properties of silicon in wafer form but the nanomembranes are flexible. By varying the thicknesses of the silicon and silicon-germanium layers composing them, membrane shapes are possible ranging from flat to curved to tubular.Potential applications include flexible electronic devices, faster transistors, nano-size photonic crystals that steer light, and lightweight sensors for detecting toxins in the environment or biological events in cells.The scientists made a three-layer nanomembrane composed of a thin silicon-germanium layer sandwiched between two silicon layers of similar thinness.

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June 2nd, 2006

Posted In: Chemistry, Materials chemistry, Nanoscience and nanotechnology

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Nobel laureate Richard Smalley, the Rice University professor who helped discover buckyballs (buckminsterfullerene, C60, the football (soccer) ball shaped form of carbon, died at the age of 62.

Richard Smalley shared the 1996 Nobel Prize in chemistry with Sir Harold Kroto (Sussex) and Robert Curl (also Rice) for the identification of the new form of carbon known as buckminsterfullerene because of its similarity to Buckminster Fuller’s geodesic domes.

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October 28th, 2005

Posted In: Chemistry, Nanoscience and nanotechnology

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