Nanotech Cotton Kills Pathogens Expensive Water Filters Can't





By dipping plain cotton fabric into a high-tech broth of silver nanowire and carbon nanotubes, Standford scientists have created a water filter capable of killing deadly pathogens other filters leave behind.

Instead of attempting to trap the bacteria and pathogens like other filtration systems, this device forces them through an electrical field that runs through the highly conductive "nano-coated" cotton.

As the bacterial passes through the filter, it is killed instantly, rendering the polluted water harmless to human drinkers.

In lab tests, over 98 percent of Escherichia coli bacteria that were exposed to 20 volts of electricity in the filter for several seconds were killed. Multiple layers of fabric were used to make the filter 2.5 inches thick (Futurity.org).

Reserachers involved in the study claim that this could be a new high-speed, low-cost water treatment method for remote areas where people don't have access to chemical treatments such as chlorine.

Traditional filters use fabrics or sand with very small pore spaces to trap waterborne bacteria, but this results in a very restricted flow rate, meaning it takes a long time to filter a large amount of water.

Because the nano-cotton doesn't need to trap the bacteria, it has much larger pores which allow a flow rate that is 80,000 times faster than traditional filters.

Waterborne diseases are on the rise, especially in countries without dependable infrastructure, or the ability to deal with natural disasters that can contaminate water supplies, such as the recent flooding in Pakistan.

The nano-filtration device can deliver almost 100% bacteria removal with very low cost materials, and is an easy-to-distribute solution for villages and cities with at-risk water supplies.


http://www.care2.com/causes/health-policy/blog/nano-coated-cotton-water-filter/

Hmm.. Electrocuting water eh.. thought those dreams I had a bit of truth to them

High Speed Water Sterilization Using One-Dimensional Nanostructures

David T. Schoen†, Alia P. Schoen†, Liangbing Hu, Han Sun Kim, Sarah C. Heilshorn and Yi Cui*
Department of Materials Science and Engineering, Stanford University, Stanford, California 94305


Abstact:




The removal of bacteria and other organisms from water is an extremely important process, not only for drinking and sanitation but also industrially as biofouling is a commonplace and serious problem. We here present a textile based multiscale device for the high speed electrical sterilization of water using silver nanowires, carbon nanotubes, and cotton. This approach, which combines several materials spanning three very different length scales with simple dying based fabrication, makes a gravity fed device operating at 100000 L/(h m2) which can inactivate >98% of bacteria with only several seconds of total incubation time. This excellent performance is enabled by the use of an electrical mechanism rather than size exclusion, while the very high surface area of the device coupled with large electric field concentrations near the silver nanowire tips allows for effective bacterial inactivation.


Full Article


This is a "good" nanotech story.

Generally Nanotech has scary dimensions for me - especially when they start wanting to put NT into our Meds and Food!!