Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Nano-coatings release almost no nano-particles: Silver in the washing machine

Symbol PictureSource: istockphoto.com
Symbol Picture

Source: istockphoto.com

Abstract:
The antibacterial properties of silver-coated textiles are popular in the fields of sport and medicine. A team at Empa has now investigated how different silver coatings behave in the washing machine, and they have discovered something important: textiles with nano-coatings release fewer nano-particles into the washing water than those with normal coatings.

Nano-coatings release almost no nano-particles: Silver in the washing machine

Switzerland | Posted on June 30th, 2014

If it contains 'nano', it doesn't primarily leak 'nano': at least that's true for silver-coated textiles, explains Bernd Nowack of the «Technology and Society» division at Empa. During each wash cycle a certain amount of the silver coating is washed out of the textiles and ends up in the waste water. Empa analysed this water; it turned out that nano-coated textiles release hardly any nano-particles. That's quite the opposite to ordinary coatings, where a lot of different silver particles were found. Moreover, nano-coated silver textiles generally lose less silver during washing. This is because considerably less silver is incorporated into textile fabrics with nano-coating, and so it is released in smaller quantities for the antibacterial effect than is the case with ordinary coatings. A surprising result that has a transformative effect on future analyses and on the treatment of silver textiles. «All silver textiles behave in a similar manner - regardless of whether they are nano-coated or conventionally-coated,» says Nowack. This is why nano-textiles should not be subjected to stricter regulation than textiles with conventional silver-coatings, and this is relevant for current discussions concerning possible special regulations for nano-silver.
But what is the significance of silver particles in waste water? Exposed silver reacts with the (small quantities of) sulphur in the air to form silver sulphite, and the same process takes place in the waste water treatment plant. The silver sulphite, which is insoluble, settles at the bottom of the sedimentation tank and is subsequently incinerated with the sewage sludge. So hardly any of the silver from the waste water remains in the environment. Silver is harmless because it is relatively non-toxic for humans. Even if silver particles are released from the textile fabric as a result of strong sweating, they are not absorbed by healthy skin.

Which detergent for which coating?
Next, Nowack's team wants to investigate how silver textiles respond to various ordinary laundry detergents. Studies have shown that some active ingredients of laundry detergents can alter the form in which silver is present. For example, before washing researchers have detected silver ions, i.e. dissolved silver (a conventional form of silver) in textile fabrics, whereas after washing they detected elemental, i.e. metallic, nano-silver or other silver compounds, such as (insoluble) silver chloride.
So silver textiles ultimately contain a number of silver compounds that constantly change and undergo chemical transformations. And they don't just do that during washing, as Nowack stresses. «Even during the manufacturing and coating processes, external influences can have an effect on the composition of the silver particles in textiles, even before the customer has got the product hanging in their wardrobe at home.

####

For more information, please click here

Contacts:
Cornelia Zogg

41-587-654-599

Prof. Dr. Bernd Nowack
Technology and Society
phone +41 58 765 76 92

Copyright © EMPA

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

When mediated by superconductivity, light pushes matter million times more April 28th, 2015

Chemists strike nano-gold: 4 new atomic structures for gold nanoparticle clusters: Research builds upon work by Nobel Prize-winning team from Stanford University April 28th, 2015

More is less in novel electronic material: Adding electrons actually shrinks the system April 27th, 2015

Two-dimensional semiconductor comes clean April 27th, 2015

Discoveries

When mediated by superconductivity, light pushes matter million times more April 28th, 2015

Chemists strike nano-gold: 4 new atomic structures for gold nanoparticle clusters: Research builds upon work by Nobel Prize-winning team from Stanford University April 28th, 2015

Scientists join forces to reveal the mass and shape of single molecules April 27th, 2015

Sensor Designed in Iran Able to Remove Formaldehyde Gas from Environment April 27th, 2015

Announcements

When mediated by superconductivity, light pushes matter million times more April 28th, 2015

Chemists strike nano-gold: 4 new atomic structures for gold nanoparticle clusters: Research builds upon work by Nobel Prize-winning team from Stanford University April 28th, 2015

Graphenea celebrates fifth anniversary April 27th, 2015

Sensor Designed in Iran Able to Remove Formaldehyde Gas from Environment April 27th, 2015

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

When mediated by superconductivity, light pushes matter million times more April 28th, 2015

Two-dimensional semiconductor comes clean April 27th, 2015

Scientists join forces to reveal the mass and shape of single molecules April 27th, 2015

Sensor Designed in Iran Able to Remove Formaldehyde Gas from Environment April 27th, 2015

Textiles/Clothing

Sensor Designed in Iran Able to Remove Formaldehyde Gas from Environment April 27th, 2015

Nanocomposites Play Effective Role in Production of Smart Fibers April 18th, 2015

Inkjet-printed liquid metal could bring wearable tech, soft robotics April 8th, 2015

FibeRio and VF Corporation Form Strategic Partnership to Lead the Apparel and Footwear Markets in Nanofiber Technology April 8th, 2015

Safety-Nanoparticles/Risk management

MIPT researchers put safety of magic anti-cancer bullet to test April 6th, 2015

NNI Publishes Workshop Report Assessing the Status of EHS Risk Science: Report examines progress three years after the release of the 2011 NNI EHS Research Strategy March 23rd, 2015

Are current water treatment methods sufficient to remove harmful engineered nanoparticle? March 10th, 2015

More study needed to clarify impact of cellulose nanocrystals on health: Few studies explore toxicity of cellulose nanocrystals March 10th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project