CARBON NANO - Size Matters
July 9, 2009 by Ambassador of Green
Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 28,000,000:1, which is significantly larger than any other material. These cylindrical carbon molecules have novel properties that make them potentially useful in many applications in nanotechnology, electronics, optics and other fields of materials science.
Carbon gets a lot of hits in the blame game but in reality its how it gets used that matters most.
WASHINGTON — Imagine a carbon sheet that’s only one atom thick but is stronger than diamond and conducts electricity 100 times faster than the silicon in computer chips.
That’s graphene, the latest wonder material coming out of science laboratories around the world. It’s creating tremendous buzz among physicists, chemists and electronic engineers.
“It is the thinnest known material in the universe, and the strongest ever measured,” Andre Geim, a physicist at the University of Manchester, England, wrote in the June 19 issue of the journal Science.
“A few grams could cover a football field,” said Rod Ruoff, a graphene researcher at the University of Texas, Austin, in an e-mail. A gram is about 1/30th of an ounce.
Like diamond, graphene is pure carbon. It forms a six-sided mesh of atoms that, through an electron microscope, looks like a honeycomb or piece of chicken wire. Despite its strength, it’s as flexible as plastic wrap and can be bent, folded or rolled up like a scroll. Graphite, the lead in a pencil, is made of stacks of graphene layers. Although each individual layer is tough, the bonds between them are weak, so they slip off easily and leave a dark mark when you write.
Potential graphene applications include touch screens, solar cells, energy storage devices, cell phones and, eventually, high-speed computer chips. Replacing silicon, the basic electronic material in computer chips, however, “is a long way off . . . far beyond the horizon,” said Geim, who first discovered how to produce graphene five years ago.
Until last year, the only way to make graphene was to mount flakes of graphite on sticky tape and separate a single layer by carefully peeling away the tape. They called it the “Scotch Tape technique.”
Recently, however, scientists have discovered a more efficient way to produce graphene on an underlying base of copper, nickel or silicon, which subsequently is etched away.
“There has been spectacular progress in the last two or three months,” Geim reported in the journal Science. “Challenges that looked so daunting just two years ago have suddenly shrunk, if not evaporated.”
Carbon bonds are infact what keep you and me going, and the more we put our understanding to use in this regard, the more likely we will be able to manage how its used.