Anti-bacterial soaps, cleansers and disinfectants are among the most commonly sold products in the U.S. today. But what if the consumer goods you buy could be made from materials that continually repel bacteria – as well as fungi and other microbes – and never need cleaning?
That’s the promise of a new class of plastics developed by German scientists that incorporate titanium dioxide molecules that interact with sunlight to destroy bacteria and other microbiological agents.
Tests of the plastics used in outdoor pool and garden furniture found they effectively blocked the growth of bacteria, fungi, algae and even moss – for up to two years.
Researchers at the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB in Stuttgart, who developed the plastics, said UV light “activates” titanium dioxide molecules to trigger an electrochemical reaction that “strikes a fatal blow” to microbes.
Dr. Iris Trick and colleagues at IGB sprayed coated and uncoated armrests with a mixture of various bacteria, mosses, algae and fungi and then left them exposed to the weather for two years. At the end of the test, they reported, it was almost impossible to remove the layer of dirt from the normal armrests, but the armrests coated with the plastics were completely clean and white.
The team of scientists calls the new products “photocatalytic coatings” and said they have a variety of applications beyond garden furniture – from self-cleaning walls to glass surfaces to paints and even smartphone screens.
“If you apply a thin coating of titanium dioxide to a glass surface such as a smartphone screen, the skin oils and fingerprints gradually disappear from the display by themselves” when exposed to sunlight, said Dr. Michael Vergöhl, with the Fraunhofer Institute.
Researchers said they are now working to develop new materials that can also be activated by artificial light.