ACS News Service Weekly PressPac: November 28, 2007

• First identification of blood on sculptures from ancient Kingdom of Mali
• New fuel cell cleans up pollution and produces electricity
• “Nanohybrid” plastic may expand use of biodegradable plastic
• Bioprospectors identify hot new biofuel-producing bacteria
• Methanol shows increasing promise as an alternative fuel

Scientists in France are reporting for the first time that sculptors from the fantastically wealthy ancient Empire of Mali — once the source of almost half the world’s gold — used blood to form the beautiful patina, or coating, on their works of art. In a study scheduled for the Dec. 15 issue of ACS’ Analytical Chemistry, a semi-monthly journal, Pascale Richardin and colleagues describe development of a new, noninvasive test that accurately identifies traces of blood apparently left on ancient African artifacts used in ceremonies involving animal sacrifices.

Archaeologists often had reported or suspected the presence of blood on many African artifacts, the study points out. However, accurately identifying the presence of blood was difficult because of the tiny amounts of blood remaining over the ages.

The researchers describe use of three highly sensitive tests — time-of-flight secondary ion mass spectrometry, infrared microscopy, and X-ray microfluoresence — to identify iron-bound (the chemical fingerprint of blood) on the patina from seven Dogon and Bamana sculptures from Mali. The technique, which caused virtually no damage to priceless artworks, also is suitable for identification of blood on other ancient artifacts, the study states.

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Scientists in New York are reporting development of a new biodegradable “nanohybrid” plastic that can be engineered to decompose much faster than existing plastics used in everything from soft drink bottles to medical implants. The study is scheduled for the Nov. issue of ACS’ Biomacromolecules, a bi-monthly journal.

The plastic is a modified form of polyhydroxybutyrate (PHB), a promising biodegradable plastic produced from bacteria that has been widely hailed as a “green” alternative to petroleum-based plastic for use in packaging, agricultural and biomedical applications. Although commercially available since the 1980s, PHB has seen only limited use because of its brittleness and unpredictable biodegradation rates.

In the new study, Emmanuel P. Giannelis and colleagues compared the strength and biodegradation rates of raw PHB to a modified form of PHB that contains nanoparticles of clay or “nanoclays.” The scientists found that the modified PHB was stronger and decomposed faster than regular PHB. The nanohybrid PHB decomposed almost completely after seven weeks, while its traditional counterpart showed almost no decomposition. Researchers also showed that degradation could be fine-tuned by adjusting the amount of nanoparticles added. The study is the “first report of the biodegradation of PHB nanocomposites” and could lead to wider use of PHB plastics, the scientists say.

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After grabbing headlines for years as the ultimate solution to world energy problems, the “hydrogen economy” has an emerging but lesser-known competitor called the “methanol economy,” according to an article scheduled for the Dec. 3 issue of Chemical & Engineering News, ACS’ weekly newsmagazine.

In the article, C&EN Associate Editor Jyllian Kemsley describes how methanol, an alcohol like ethanol, shows increasing promise as an alternative energy source with advantages over both ethanol and hydrogen. A methanol economy — championed in a 2006 book by chemistry Nobel Laureate George Olah — would not be dependent on bumper crops of corn and could provide lower tailpipe emissions and a reduced fire hazard. Besides powering automobile engines, methanol can also be used to power fuel cells and as a fuel for operating gas turbines at electric power plants, the article notes. It also can take the place of petroleum-based feedstocks for making a range of chemicals and materials, including plastics.

China now blazes the trail toward a methanol economy, putting 1 to 2 billion gallons per year toward fuel, according to the article. Researchers worldwide are now exploring new, more efficient methods for making methanol. One of the downsides of producing methanol, however, is that carbon dioxide, the primary gas behind climate change, is a byproduct. To remove that liability, scientists are also developing processes that can convert the carbon dioxide into more methanol or other usable materials, the article states.

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• Bytesize Science, a podcast for young listeners The American Chemical Society (ACS) Office of Communications has launched Bytesize Science, an educational, entertaining podcast for young listeners. Bytesize Science translates cutting-edge scientific discoveries from ACS' 36 peer-reviewed journals into stories for young listeners about science, health, medicine, energy, food, and other topics. New installments of Bytesize Science are posted every Monday and available without charge. The archive includes items on environmental threats to killer whales, a scientific explanation for why some people love chocolate, the possible medical uses of an intriguing substance known as “dragon’s blood,” and a hairy tale about "hairy roots." The podcaster for Bytesize Science is Adam Dylewski, an ACS science writer and recent graduate of the University of Wisconsin-Madison with degrees in genetics and science communication.
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• Science Elements: An ACS Science News Podcast
  The ACS Office of Communications is podcasting PressPac contents in order to make cutting-edge scientific discoveries from ACS journals available to a broad public audience at no charge. Science Elements includes selected content from ACS’s prestigious suite of 36 peer-reviewed scientific journals and Chemical & Engineering News, ACS’s weekly news magazine. Those journals, published by the world’s largest scientific society, contain about 30,000 scientific reports from scientists around the world each year. The reports include discoveries in medicine, health, nutrition, energy, the environment and other fields that span science’s horizons from astronomy to zoology. Podcaster for Science Elements is Steve Showalter, Ph.D., a chemist at the U. S. Department of Energy’s Sandia National Laboratories in Albuquerque, New Mexico, and ACS member.

• Highlights, resources from ACS Chocolate Workshop now online
• American Chemical Society’s workshop, 'Cooks with Chemistry —The Elements of Chocolate' provided reporters with a delectable assortment of new information on the world’s favorite treat. Held Oct. 11, 2007, at the Institute of Culinary Education in New York City and sponsored by the ACS Office of Communications, the chocolate workshop featured presentations from Harold McGee and Shirley Corriher, award-winning cookbook authors, and Sara Risch, the noted food and flavor chemist. With chocolate consumption nearing an annual peak as the holidays approach, we are providing content from this event to news media unable to attend the workshop. The material includes ACS journal articles about the chemistry of chocolate; advice for cooks who run into trouble with chocolate recipes; tips on how to successfully use “new” chocolates in old favorite recipes; and a fascinating comparison of the health benefits and flavor components of different kinds of chocolate. For interviews with the chocolate workshop participants or other information, please contact newsroom@acs.org.
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