Sunday, November 9, 2008

Using Tungsten to freeze water at room temperature


This is pretty weird. It turns out that water can freeze at room temperature in response to atomic-scale friction.

Joost Frenken and others at Leiden University used an instrument called a friction force microscope to create nano-friction by dragging a tungsten wire over a graphite surface. They wanted to test the theory that water vapour in the air might condense and become ice. And it did.

They were even able to draw frozen patterns on the graphite surface. They think that "icy nanoscale water bridges" form as water vapour condenses in the nanoscopic gaps between the two surfaces.

So far, so strange. But the researchers say the discovery could also have practical uses. This is because the tiny frozen bridges turn water from a lubricant into a kind of glue. So the effect could be important in the future for building nanoscale devices or structures. Curiously, there are other ways to turn water to ice at room temperature, such as using electric fields.

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