Chemistry

Computers are getting smaller and smaller and as hand-held devices like mobile phones and music players get more powerful the race is on to develop memory formats that can satisfy the ever-growing demand for information storage on those tiny formats.

Current memory technologies fall into three separate groups: dynamic random access memory (DRAM), which is the cheapest method; static random access memory (SRAM), which is the fastest memory — but both DRAM and SRAM require an external power supply to retain data; and flash memory, which is non-volatile — it does not need a power supply to retain data, but has slower read-write cycles than DRAM.
Chemistry researchers at The University of Warwick and the John Innes Centre, have found a novel signalling molecule that could be a key that will open up hundreds of new antibiotics unlocking them from the DNA of the Streptomyces family of bacteria.
I recently attended an NSF workshop on eChemistry: New Models for Scholarly Communication in Chemistry in Washington (Oct 23-24, 2008). The group consisted of about a dozen members, including publishers, social scientists, librarians and chemists. For background, this was the mandate:
The first-ever glimpse of nanoscale catalysts in action could lead to improved pollution control and fuel cell technologies. Scientists from the U.S. Department of Energy's Lawrence Berkeley National Laboratory observed catalysts restructuring themselves in response to various gases swirling around them, like a chameleon changing its color to match its surroundings.

Using a state-of-the-art spectroscopy system at Berkeley Lab's Advanced Light Source, the team watched, for the first time, as nanoparticles composed of two catalytic metals changed their composition in the presence of different reactants. Until now, scientists have had to rely on snapshots of catalysts taken before and after a reaction, never during.
Scientists in Spain are reporting an advance toward a new method for determining the purity of heroin that could save lives by allowing investigators to quickly identify impure and more toxic forms of the drug being sold on the street. Unlike conventional tests, it does not destroy the original drug sample, according to their report.

In the new study, Salvador Garrigues and colleagues point out that the purity of heroin can vary widely, since pushers often mix it with chalk, flour, or other "cutting agents." Because heroin users do not know the exact purity of the drug, they are more at risk for overdose and even death. Conventional tests for determining the purity of street heroin involve destructive and time-consuming sample preparation, the scientists say.


New nanotechnology paints for walls, ceilings, and surfaces could be used to kill hospital superbugs when fluorescent lights are switched on, said scientists today at the Society for General Microbiology's Autumn meeting being held this week at Trinity College, Dublin.

The new paints contain tiny particles of titanium dioxide, which is the dazzling white compound often used as a brightener in commercial paints. It will also be familiar to tennis fans as the powder used for the white lines to mark out the courts at Wimbledon.

Virginia Tech chemistry Professor Harry Dorn has developed a new area of fullerene chemistry that may be the backbone for development of molecular semiconductors and quantum computing applications.

Dorn plays with the hollow carbon molecules known as fullerenes as if they are tinker toys. First, in 1999, he figured out how to put atoms inside the 80-atom molecule, then how to do it reliably, how to change the number of atoms forming the carbon cage, and how to change the number and kinds of atoms inside the cage, resulting in a new, more sensitive MRI material and a vehicle to deliver radioactive atoms for applications in nuclear medicine.


Researchers from the National Institute of Standards and Technology (NIST) and Seoul National University (SNU) have learned how to tweak a new class of polymer-based semiconductors to better control the location and alignment of the components of the blend.

Their recent results—how to move the top to the bottom—could enable the design of practical, large-scale manufacturing techniques for a wide range of printable, flexible electronic displays and other devices.

Organic semiconductors—novel carbon-based molecules that have similar electrical properties to more conventional semiconducting materials like silicon and germanium—are a hot research topic because practical, high-performance organic semiconductors would open up whole new categories of futuristic electronic devices. Think of tabloid-sized “digital paper” that you could fold up into your pocket or huge sheets of photovoltaic cells that are dirt cheap because they’re manufactured by—basically—ink-jet printing.


LLNL researchers care about the environment too. To keep Mother Nature safe while we blow stuff up, they have added unique green solvents (ionic liquids) to an explosive called TATB (1,3,5-triamino-2,4,6-trinitrobenzene) and improved the crystal quality and chemical purity of the material.

Most explosives belong to a general class of materials called molecular crystals, which have become important building blocks in a number of other applications ranging from drugs, pigments, agrochemicals, dyes and optoelectronics. Many of these materials, including TATB, are bound together by a strong network of hydrogen-bonds. This extended network often makes these materials nearly insoluble in common organic solvents, leading to poor quality and limited size crystals, which in turn hinders progress in many technological applications.

The semiconductor silicon and the ferromagnet iron are the basis for much of mankind's technology, used in everything from computers to electric motors.

Writing in Nature, an international group of scientists from the UK, USA and Lesotho report that they have combined these elements with a small amount of another common metal, manganese, to create a new material which is neither a magnet nor an ordinary semiconductor.

They then show how a small magnetic field can be used to switch ordinary semiconducting behavior (such as that seen in the electronic-grade silicon which is used to make transistors) back on.