Friday, February 12, 2010

This week in nanotechnology - February 12, 2010

Chemists report creating a synthetic 'gene' – a DNA-like crystal – that could capture heat-trapping carbon dioxide emissions, which contribute to global warming, rising sea levels and the increased acidity of oceans.

Researchers at the California Institute of Technology (Caltech) have developed a way to make some notoriously brittle materials ductile – yet stronger than ever – simply by reducing their size down to the nanoscale. This work could eventually lead to the development of innovative, superstrong, yet light and damage-tolerant materials.

Just as the heartbeats of today's electronic devices depend on the ability to switch the flow of electricity in semiconductors on and off with lightning speed, the viability of the "spintronic" devices of the future -- technologies that manipulate both the flow and magnetic "spin" of electrons – will require similarly precise control over semiconductor magnetism. Scientists have now observed electrons in a semiconductor on the brink of the metal-insulator transition for the first time.

electrons on the brink of the metal-insulator transition


On the brink of the metal-insulator transition, the electrons in a manganese-doped gallium arsenide semiconductor are distributed across the surface of the material in complex, fractal-like patterns. These shapes are visible in this electron map, where the colors red, orange and yellow indicate areas on the surface of the semiconductor where electrons are most likely to be found at a given point in time. In this image, the fractal-like probability map of electrons is superimposed on the atomic crystal structure of the material, imaged at the same time.


University of Florida scientists have developed a new nanoparticle that could improve cancer detection and drug delivery. The particle, called a 'micelle' and made up of a cluster of molecules called aptamers, easily recognizes tumors and binds strongly to them. It also has properties that allow it to easily get inside cells for intracellular studies and drug delivery.

Physicists have for the first time observed chemical reactions near absolute zero, demonstrating that chemistry is possible at ultralow temperatures and that reaction rates can be controlled using quantum mechanics, the peculiar rules of submicroscopic physics.

Researchers in China are making carbon nanotube sponges consisting of a large amount of interconnected nanotubes, thus showing a combination of useful properties such as high porosity, super elasticity, robustness, and little weight. The CNT sponges are capable of absorbing a wide range of solvents and oils with excellent selectivity, recyclability, and absorption capacities up to 180 times their own weight, two orders of magnitude higher than activated carbon.