Tuesday, October 14, 2014

lucy in the sky with diamonds....,


BI |  John Badding of Penn State University and his team discovered that liquid benzene, when subjected to extreme pressure (around 200,000 times the pressure at the surface of the Earth) and then slowly relieved of that pressure, forms extremely thin, tight rings of carbon that are structurally identical to diamonds.

In other words, if you could unravel a diamond like you can a piece of fabric, you'd get these far-out threads. The result is a chain, thousands of times thinner than a human hair, that has the potential to be the strongest, stiffest material ever discovered. 

The discovery was something of an accident, but far from a hapless one. The team used a large, high-pressure device called the Paris-Edinburgh device at Tennessee's Oak Ridge National Laboratory to compress a 6-millimeter wide quantity of liquid benzene — a huge amount compared with previous experiments. The volume of liquid benzene, coupled with the size of the device, forced them to relieve the pressure more slowly than they would have otherwise.

"It's been known for a long time that if you put benzene under pressure, it’d make a type of polymer," Badding told Business Insider. "An Italian team did a similar experiment and found it was amorphous, disordered, with no pattern to the way material’s held together, kind of like glass. We were trying to make the same material everyone else had made, but in larger quantities."

When they released the pressure, "something interesting happened: the material became ordered," Badding said. The carbon atoms in the liquid benzene arranged themselves so that each was linked with four others, in what's called a tetrahedral structure. Structurally, the threads formed by the liquid benzene are identical to diamond, with each carbon atom linked with four others. You can see what they look like below. 

It was the breakthrough that Badding had been seeking for 20 years.

"Luck favors the prepared mind," Badding said. "I’d love to be able to say I predicted this was going to happen for benzene. I don’t think I can say that. But in a way our studies in benzene were a step in this larger goal, and we just happened to find that faster than we thought we would."

Now that Badding and his colleagues have shown that this structure is possible, the next step is to confirm the precise structure of the material and look for any imperfections that might exist.
"Theory suggests that if you can make the structures perfect, they could be as strong or stronger than carbon nanotubes, but we have not confirmed that experimentally," Badding said.

Going up
Towards the end of his life, science fiction writer Sir Arthur C. Clarke predicted that a space elevator would be built ten years after everybody stopped laughing. By the time he died, in 2008, everybody had.