The Alchemist Newsletter: March 25, 2011

The Alchemist this week learns of efforts to mimic the tough shells of the sea snail known as the queen conch, a discovery for William Golding fans perhaps. In other materials news, nanoscopic spirals could improve computer storage while a new approach to testing water reveals the nature of river pollutants in Spain. A chemical solution to an environmental problem could see a reduction in the potent greenhouse gas dinitrogen monoxide entering the atmosphere from livestock urine. In chemical testing, a new robotic arm to the Tox21 initiative could accelerate identification of problem compounds and reconcile the reputation of some substances. Finally, modern alchemy falls foul of earthquakes, tsunami, and media scaremongering.

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Tough as conch

A review of the literature by Cambridge chemist reveals that the nanoscopic structure of conch shells might be used as a model for creating composite materials as tough as steel but much less dense and perhaps far less costly to make in terms of energy and expense. The team discusses how the shell of the queen conch despite being little more than calcium carbonate and some organic matter is formed from nanoscopic single crystals in a cross-layered 3D structure that makes it as tough as mild steel pound for pound. This nanocrystalline structure prevents cracks from propagating through the shell. However, to make a truly biomimetic material, researchers will not only have to find a way to copy this structure they will also have to develop technology to heal any tiny cracks that form, something the living sea snail does with little effort in its battle against turtle jaws and crab claws.

Conch shell gives nano insights into composite materials

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Storage in a whirl

The discovery that nanoscale spirals can be formed in the electric polarization of ferroelectric materials at controllable intervals could lead to a fundamentally new approach to information storage. "To change the state of a ferroelectric memory, you have to supply enough electric field to induce a small region to switch the polarization. With our material, such a nucleation process is not necessary," explains Xiaoqing Pan of the University of Michigan. "The nucleation sites are intrinsically there at the material interfaces." With colleagues at U-M and collaborators from Cornell University, Penn State University, and University of Wisconsin, Madison, Pan has designed a material system that spontaneously forms these nanospirals. The work could lead to memory devices with more storage capacity than magnetic hard drives and faster write speed and longer lifetimes than flash memory.

Fundamental discovery could lead to better memory chips

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Water's secret scents

An entirely new approach to testing water can reveal the presence of trace quantities of non-polar and semi-polar organic pollutants, according to research published in the journal Analytical Chemistry. Environmental and industrial water samples can contain a wide range of contaminants. So, researchers in Spain are using a polymer-coated stir bar in their sample vessel with a pinch of salt and some methanol, all heated overnight to encourage contaminants to be absorbed on to the polymer. Gas chromatographic separation over contaminants released by heating the polymer the next day can then feed into a mass spectrometer and give them signals on even the tiniest quantities of pollutants, below 1 nanogram per liter. Proof of principle was undertaken on samples from the Henares River, which revealed personal care products such as fragrances to be the most abundant and persistent contaminants in the river water samples.

Water samples yield their secrets

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Burning for nitrous

Might biochar be a useful material to ameliorate release of the potent greenhouse gas nitrous oxide from agricultural sources? Researchers at Lincoln University in New Zealand have carried out a three-month test over the spring-summer period to determine what effect incorporating biochar into soil on land grazed by cattle might have. Nitrous oxide emissions from bovine urine is an important source of atmospheric nitrous oxide. Arezoo Taghizadeh-Toosi and colleagues found that the presence of biochar led to a a 70% reduction in nitrous oxide flux over the course of the study. Details are published in The Journal of Environmental Quality.

Can Biochar Help Suppress Greenhouse Gases?

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Testing times for tox robot

A new robotic system is set to test 10,000 chemicals commonly found in industrial and consumer products, food additives and pharmaceuticals. The compound list was compiled from 200 public databases and testing under the Tox21 program will provide science-based data useful in evaluating whether or not a wide range of chemicals has potential health effects. The system uses 1536-well microtiter plates, which allows the robot to handle 1408 samples and controls on a single per plate. Each plate represents a different concentration of the compounds to be tested. "Tox21 has used robots to screen chemicals since 2008 [more than 2,500 tested so far], but this new robotic system is dedicated to screening a much larger compound library," explains NHGRI Director Eric Green.

New robot system to test 10,000 chemicals for toxicity

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Nuclear issues

Recent seismic events in Japan and significant damage to nuclear facilities there have left the world reeling and given anti-nuclear activists more fuel for their argument. At the time of writing, the full impact of these events had not been determined. However, political fallout is already causing problems for the nuclear industry as a whole and for the future of this potent alternative to electricity generation based on fossils fuels. The specific impact of damage at Fukushima remains to be seen. If these old reactors are brought under total control with little radiation dispersal then the final result for nuclear power in the future might be more positive. Given the scaremongering in the mass media and kneejerk reactions from some politicians across the globe, The Alchemist wonders whether this is likely.

Uncertainty for nuclear power

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