Tuesday, July 31, 2007
Posted by Chismillionare at 12:33 PM
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Researchers at the University of California, Berkeley, have found an easy way to make a complex nanostructure that consists of tiny rods studded with nanocrystals. The new self-assembly synthesis method could lead to intricate nanomaterials for more-efficient solar cells and less expensive devices for directly converting heat into electricity.
In the structures, the quantum dots are all about the same size and are spaced evenly along the rods--a feat that in the past required special conditions such as a vacuum, with researchers carefully controlling the size and spacing of different materials, says Paul Alivisatos, the professor of chemistry and materials science at Berkeley who led the work. In contrast, Alivisatos simply mixes together the appropriate starting materials in a solution; these materials then arrange themselves into the orderly structure.
Posted by Chismillionare at 10:10 AM
Researchers at the University of Sheffield, in the UK, have made an adhesive that can be turned on and off with an external switch. The switch is the acidity of the solution surrounding the glue: two different kinds of polymers in the glue attract each other based on the solution's acidity. By repeatedly making the solution less or more acidic, Mark Geoghegan and his colleagues can switch the adhesive's stickiness, making two surfaces bond together and then come apart up to five times
Posted by Chismillionare at 10:08 AM
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