Recycled LCD component fights bacterial infections

Your TV may someday save your life. Scientists in the United Kingdom have discovered a way to turn one of the chemical compounds used in LCD screens into an anti-microbial substance that has the potential to fight deadly infections and safely deliver drugs. Once altered, researchers report that the chemical compound polyvinyl-alcohol (PVA) is strong enough to kill E. coli and some strains of Staphylococcus aureus.

Liquid crystal displays, used in flat-screen televisions and digital clocks among other products, have become one of the fastest growing sources of waste in the United States and European Union. Finding ways to re-use chemicals like PVA once they've reached their end-of-life stage will be critical in reducing the waste produced by electronics. Less than 20 percent of electronic waste is recycled each year, according to the U.S. Environmental Protection Agency.

To convert the chemical into a human-friendly substance, researchers at the University of York microwaved the PVA, then dehydrated it in an ethanol wash. This creates an expanded, porous material that doesn't stir the immune system to attack, which is important because that means it can be used in dressings and pills as well as scaffolding for skin grafts. The addition of silver nanoparticles gives the material its bacteria-killing characteristics. Researchers hope it will be used in biomedicine and in hospital cleaning products.

The PVA-based substance has not yet been compared to commercial products in terms of effectiveness, and regulatory agencies have not yet approved silver nanoparticles for use in human health.

While a possible use for PVA has been found, other elements of LCDs continue to be discarded as waste. Nitrogen trifluoride is generated during the manufacture of LCDs and appears to be released as a strong greenhouse gas. According NASA-funded measurements, it survives in the atmosphere nearly five times longer than carbon dioxide and is a more powerful agent of global warming than both carbon dioxide and methane. Nitrogen trifluoride emissions also aren't regulated under the Kyoto Protocol because the trace amount present in the atmosphere in 1997 was considered insignificant. That amount has increased exponentially with the development of LCD technology.

"At present there are no commercially viable, environmentally friendly solutions either for recovery and/or purification of LCD waste," states Dr. Avtar Matharu at the University of York Department of Chemistry. Until we reach a viable solution, don't celebrate your TV yet.