Friday, November 12, 2010

This week in nanotechnology - November 12, 2010

Low-cost, hybrid thermoelectrics: Historically, high-efficiency thermoelectrics have required high-cost, materials-intensive processing. By engineering a hybrid of soft and hard materials using straightforward flask chemistry in water, researchers at the Berkeley Lab have now developed a route that provides respectable efficiency with a low cost to production.

Andre Geim, who along with his colleague  Kostya Novoselov won the 2010 Nobel Prize for graphene, has now modified it to make fluorographene – a one-molecule-thick material chemically similar to Teflon. The team hope that fluorographene, which is a flat, crystal version of Teflon and is mechanically as strong as graphene, could be used as a thinner, lighter version of Teflon, but could also be in electronics, such as for new types of LED devices.

In other graphene news, Empa researchers have fabricated graphene-like materials using a surface chemical route and clarified in detail the corresponding reaction pathway. Understanding chemical reactions in detail helps to control them and enables to tailor graphene products.

The scanning tunnelling microscope images shows nanographene molecules and the two stabilized intermediate products on a copper surface. The molecular models show a nanographene (at the bottom right) as well as the two intermediate products (above and left). In reality the diameter of the molecule is approximately one nanometer.

Scientists at the Institute of Bioengineering and Nanotechnology in Singapore have devised a new environmentally friendly technique to transform carbon dioxide, an abundant and renewable carbon source, into highly functionalized propiolic acids, which are basic building blocks for the synthesis of a wide range of pharmaceuticals such as cholesterol-reducing drugs and peptidomimetic and other small molecule inhibitors that may be used, for example, to kill cancer cells.

Nanogenerators grow strong enough to power small conventional electronics: The nanogenerators devised in the laboratory of Zhong Lin Wang at Georgia Tech rely on the piezoelectric effect seen in crystalline materials such as zinc oxide, in which an electric charge potential is created when structures made from the material are flexed or compressed. By capturing and combining the charges from millions of these nanoscale zinc oxide wires, Wang and his research team can produce as much as three volts – and up to 300 nanoamps.

Quantum computers should be much easier to build than previously thought, because they can still work with a large number of faulty or even missing components. This surprising discovery brings scientists one step closer to designing and building real-life quantum computing systems – devices that could have enormous potential across a wide range of fields, from drug design, electronics, and even code-breaking.

A greener way to grow carbon nanotubes: It turns out that one process commonly used to produce carbon nanotubes may release several hundred tons of chemicals, including greenhouse gases and hazardous air pollutants, into the air each year. MIT researchers report that in experiments, removing one step in that process — a step that involves heating carbon-based gases and adding key reactive "ingredients" — reduced emissions of harmful by-products at least tenfold and, in some cases, by a factor of 100. It also cut the amount of energy used in the process by half.