Nano-coated material cleans itself with light


Stain-busting nanoparticles remove stains in half an hour – but don't throw away your washing machine just yet. Phil Ritchie reports.


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Cotton textile covered with nanostructures invisible to the naked eye. Image magnified 200 times.
RMIT University

Dribbled pasta sauce down the front of your white shirt? One day you might only have to stand under the nearest lamp to clean the embarrassing spill off.

Researchers at Melbourne's RMIT University developed a cheap, quick and effective way to grow nanostructures on cotton, which can degrade organic matter when exposed to light.

The self-cleaning material, published in the journal Advanced Materials Interfaces, is created by dipping textiles into a series of solutions. After half an hour, the material is covered with stable nanostructures.

When they're exposed to visible light, such as lamplight or sunshine, the nanostructures absorb energy. This vibrates electrons, turning some into what are known as "hot electrons". Hot electrons, in turn, kick out a burst of energy which can break down organic matter.

Close-up of nanostructures grown on cotton textiles. Image magnified 150,000 times. – RMIT University

To maximise hot electron degradation power, the researchers used solutions that built copper- and silver-based nanostructures, which are particularly good light-absorbers. They saw some stains disappeared in as little as six minutes under a light.

Study co-author Rajesh Ramanathan said the cleaning process is boosted by yarn's holey nature: “The advantage of textiles is they already have a 3-D structure so they are great at absorbing light, which in turn speeds up the process of degrading organic matter.

"Our next step will be to test our nano-enhanced textiles with organic compounds that could be more relevant to consumers, to see how quickly they can handle common stains like tomato sauce or wine."

So when will we see this miracle stain-zapping material on clothes racks?

It'll be a while, Ramanathan admits: “There’s more work to do before we can start throwing out our washing machines, but this advance lays a strong foundation for the future development of fully self-cleaning textiles.”

Explore #nanoparticles
  1. http://onlinelibrary.wiley.com/doi/10.1002/admi.201670025/abstract
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