March 12, 2013 3:18 pm
DNA, deoxyribonucleic acid, is a wonderful molecule. The blueprint of all life, the little double helix holds massive amounts of information in a tightly coiled structure—a repeating sequence of limited molecular variability that provides all of life’s diversity. DNA is also, apparently, a pretty good flame retardant.
According to a new study, scientists who collected sperm from herring, isolated the DNA, dissolved it in water, rubbed it on a cotton cloth, let it dry out and set it on fire with a natural gas torch found that DNA prevents the cloth from burning. (Science is weird.)
DNA’s chemical structure makes it ideal for the flame-stopping job. When heated, its phosphate-containing backbone produces phosphoric acid, which chemically removes water from cotton fibers while leaving behind a flame-resistant, carbon-rich residue. The nitrogen-containing bases release ammonia — which dilutes flammable gases and inhibits combustion reactions — and can act as “blowing agents,” which help turn the carbon-rich deposits into a slow-burning protective layer. Ultimately, these ingredients stop combustion by forming either a carbon-rich foam, or a protective, glassy carbon coating called char.
A cotton cloth with sperm DNA:
And without sperm DNA:
The scientists say that DNA could potentially be used as a next generation flame retardant in fabrics. But it probably wouldn’t hurt their sales figures if they could find a different DNA source.
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