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Tuesday, May 30, 2006 Super Plastic Both Attracts and Repels WaterAn odd new material could be a boon in dry regions with limited access to clean water. By Prachi Patel-Predd
A new, practical method for making surfaces with patterns of areas that strongly attract and strongly repel water could lead to a highly efficient method for capturing clean water. This versatile material could also find uses in fabricating new types of devices for medical tests and chemical synthesis. Scientists have reported numerous applications of water-attracting (superhydrophilic) and water-repelling (superhydrophobic) surfaces, including fog-free eyeglasses and windshields, and self-cleaning cloth and glass. Now a group of researchers in MIT's materials science and engineering department has combined those opposing characteristics on a single surface, by using a simple and versatile fabrication process. [For images of this new dual-quality material, click here.] Robert Cohen, Michael Rubner, and colleagues started by assembling a nano-structured film made of alternating layers of positively and negatively charged polymers and silica nanoparticles. The film's structure and a coating of waxy fluorinated silane cause water to bead on it, forming near-perfect spheres that easily roll off. To add the superhydrophilic regions (to which water droplets cling), the researchers applied a naturally hydrophilic polymer to selected areas. In dry regions of the world, without easy access to clean water, such a material could be used for collecting water. In this application, the hydrophilic areas of the material would attract moisture in the air, collecting water drops that accumulate, until they spill over into the hydrophobic regions and roll into a collecting channel. Currently, in countries with limited access to clean water, the inhabitants typically use large polypropylene fiber meshes to harvest water from fog. The new technology "would provide a more than tenfold increase in water capture compared to the inefficient nets that are used currently," says Andrew Parker, a biologist at Oxford University and the Natural History Museum in London, who has studied the desert beetle that inspired the MIT work. If the new material "could be added simply to the roofs of houses in areas subjected to desert fogs," says Parker, "then a water supply could be gained with little effort." Rubner's lab is also taking the technique further. "When we harvest water, we have chemistry built into the hydrophilic area so that it has an antibacterial agent to kill off bacteria and other things that cause harm," Rubner says. This decontaminates the water as it accumulates so that the collected water is safe for use. Applying this technique, the researchers have been able to kill common harmful bacteria in four minutes, he says. |
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Comments
Guest (Ronald H Levine) on 05/30/2006 at 12:00 AM
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Guest (andrea raise) on 06/21/2006 at 12:00 AM
1
Guest (Chuck the Lucky) on 06/01/2006 at 12:00 AM
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I remember one of these companies saying that the technology is feasible in all but the absolutely driest climates and that most of the world's people, even the poorest, live in areas where it is may be hot and have little precipitation but the air is not completely dessicated. Many are selling solar panels and provide units in a range of sizes from personal/family to small village size. If this new strategy can be added on to this new but existing industry of atmospheric water generators it could be a really interesting development.
http://en.wikipedia.org/wiki/Water_Air_Extraction_Devices
Guest (bogo) on 06/02/2006 at 12:00 AM
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Guest (Austin B. Carter, Jr) on 06/04/2006 at 12:00 AM
1
coated on opposite face with an
electrical conductor that would
then allow electrostatic cooling
to depress the samples temperature
to the ambient DEW point resulting in the nucleation, condensation and
harvesting of water from air. Note
that electrostatic cooling can be
powered by a solar panel.
pablo8 on 08/21/2006 at 1:11 PM
1
pablo
awetila on 09/15/2006 at 4:56 PM
1
currently am a student of mechanical engineering in my school. I am working on a particular topic, please i need your assistance in helping me to write this.it is a competition i am putting in for.Thanks as i wait for your reply.
joeatxdobs on 09/26/2006 at 12:43 PM
1
Guest (Austin B. Carter,Jr.) on 07/03/2006 at 12:00 AM
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Nano super plastic would allow
water collection from fog and be
a small, mobile, squeezable supply
of water for mariners adrift on a
life raft in a fog bank.
rawson on 11/07/2006 at 9:49 AM
1
I represent a group of large off shore investors. I would like to request a sample,to check usage,capacity etc.If you have any research that is available that would be great also.
please send reply to rawson_watson@hotmail.com
address Mr R.Watson
237 marlborough road
Gillingham
Kent ME7 5HS
England
klm220 on 05/21/2007 at 5:45 PM
1
Congratulations on your "memorable crime"!
http://news.bbc.co.uk/1/hi/england/kent/2976574.stm
briesmith on 05/22/2007 at 7:00 AM
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This man is obviously stupid beyond belief. It would be interesting to find out what, if anything, he could make of this new material.
Failing any way forward with technology can I suggest a name change?
Michaelangelica on 01/08/2007 at 2:39 PM
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semichnich on 11/03/2007 at 10:39 PM
1