abcnews.go.com/sections/scitech/DailyNews/drywater010627.html
By stirring in a special powder with sloshing water, scientists created buckets of water beads that won't leak. Unlike regular water droplets that slide down a surface and leave a wet trail, these droplets can roll around and don't spill a thing. These "marbles" of water actually take on the properties of a spongy solid and reveal how water moves when it does not cling to surfaces. The beads' rolling motions resemble the behavior of water droplets suspended in space and, the scientists say, can lend clues about the stability and behavior of celestial bodies. The dry water marbles might also carry practical applications. The French physicists suggest the dry water beads could provide a leak-free method for transporting water. What kind of high-tech powder can make liquid behave like a solid? In fact, Aussillous and Quere found the perfect material in nature. Spores of a club moss, which are primitive, veined plants, combine to create a powder with water resistent properties -- like wax or oil. The scientists then coated the spores in extra sealant to ensure they would not mix with the water. The water resistant powder, explains Aussillous, clings only to the surface of water droplets. And since the powder blocks contact between water and a surface, the water molecules don't leak or stick to surfaces. The beads of water even float on top of a pool of regular water. The powder and water remain separate even when the beads are punctured to release their liquid interior. Traditionally, physicists have focused on creating surfaces that will cause water to bead and roll. Wax paper, for example, provides a surface on which water is likely to roll, not stick. Mahadevan of the University of Cambridge remarks in an accompanying column in Nature, "Aussillous and Quere have ingeniously inverted these ideas" by placing the nonstick surface around the water, rather than on the surface. Mahadevan adds, however, that the two physicists may not be the first to think of the idea. Some insects in nature, he says, have been observed transporting tiny, powder-coated drops of water. Tough -- for a Liquid Mahadevan suggests coated water beads could provide wear-free lubrication for tiny machines or could lead to pipes that remain totally dry (and rust-free) while transporting gallons of beaded water. But before any of those kinds of ideas can be explored, the team must first ensure the liquid beads are highly durable. The water beads also resist merging -- in tests no two water beads have joined when in contact with each other. Click here for 31 Press Information, 32 Terms of Use & 33 Privacy Policy & Internet Safety Information applicable to the site.
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