Now we have to figure
out how to make large supplies of carbyne.
Better yet we need to produce it massively in parallel in order to
generate a twisted cable from it. This
will produce a super cable three times stronger than diamond. This is presently a tall order but not
implausible.
It may even be possible
to wrap it with a nanotube formed from grapheme and twisted around a bundle of
the cable. This is surely good enough to
produce the space elevator.
Nano scale tooling is
becoming very important to produce these extreme materials. This is a huge growth industry that is well
worth pursuing.
I would not be surprised to discover
solutions much easier than we now imagine.
Carbon’s new champion
– OCTOBER
9, 2013
Rice
U. theorists calculate atom-thick carbyne chains may be strongest material
ever
HOUSTON
– (Oct. 9, 2013) – Carbyne will be the strongest of a new class of microscopic
materials if and when anyone can make it in bulk.
If
they do, they’ll find carbyne nanorods or nanoropes have a host of remarkable
and useful properties, as described in a new paper by Rice University
theoretical physicist Boris Yakobson and his group. The paper appears this week
in the American Chemical Society journal ACS
Nano.
Carbyne
is a chain of carbon atoms held together by either double or alternating single
and triple atomic bonds. That makes it a true one-dimensional material, unlike
atom-thin sheets of graphene that
have a top and a bottom or hollow nanotubes that have an inside and outside.
According
to the portrait drawn from calculations by Yakobson and his group:
*
Carbyne’s tensile strength – the ability to withstand
stretching – surpasses “that of any other known material” and is double that of graphene.
(Scientists had already calculated it would take an elephant on a
pencil to
break through a sheet of graphene.)
*
It has twice the tensile
stiffness of
graphene and carbon nanotubes and nearly three times that of diamond.
*
Stretching carbyne as little as 10 percent alters its electronic band gap
significantly.
*
If outfitted with molecular handles at the ends, it can also be twisted to
alter its band gap. With a 90-degree end-to-end rotation, it becomes a magnetic
semiconductor.
* Carbyne chains
can take on side molecules that may make the chains suitable for energy
storage.
*
The material is stable at room temperature, largely resisting crosslinks with
nearby chains.
That’s
a remarkable set of qualities for a simple string of carbon atoms, Yakobson
said.
“You
could look at it as an ultimately thin graphene ribbon, reduced to just one
atom, or an ultimately thin nanotube,” he said. It could be useful for
nanomechanical systems, in spintronic devices, as
sensors, as strong and light materials for mechanical applications or for
energy storage.
“Regardless
of the applications,” he said, “academically, it’s very exciting to know the
strongest possible assembly of atoms.”
Based
on the calculations, he said carbyne might be the highest energy state for
stable carbon. “People usually look for what is called the ‘ground state,’ the
lowest possible energy configuration for atoms,” Yakobson said. “For carbon,
that would be graphite, followed by diamond, then nanotubes, then fullerenes.
But nobody asks about the highest energy configuration. We think this may be
it, a stable structure at the highest energy possible.”
Theories
about carbyne first appeared in the 19th century, and an approximation of the
material was first synthesized in the USSR in 1960. Carbyne has since been seen
in compressed graphite, has been detected in interstellar dust and has been
created in small quantities by experimentalists.
“I
have always been interested in the stability of ultimately thin wires of
anything and how thin a rod you could make from a given chemical,” Yakobson
said. “We had a paper 10 years ago about silicon in which we explored what happens
to silicon nanowire as it gets thinner.
To me, this was just a part of the same question.”
The
Rice researchers, led by Rice graduate student Mingjie Liu and postdoctoral
researcher Vasilii Artyukhov, were aware of a number of papers that described
one property or another of carbyne. They set out to detail carbyne with
computer models using first-principle rules to determine the energetic
interactions of atoms, Artyukhov said.
“Our
intention was to put it all together, to construct a complete mechanical
picture of carbyne as a material,” Artyukhov said. “The fact that it has been
observed tells us it’s stable under tension, at least, because otherwise it
would just fall apart.”
Yakobson
said the researchers were surprised to find that the band gap in carbyne was
so sensitive to twisting. “It will be useful as a sensor for torsion or
magnetic fields, if you can find a way to attach it to something that will
make it twist,” he said. “We didn’t look for this, specifically; it came up as
a side product.”
“That’s
the good thing about studying things carefully,” Artyukhov said.
Another
finding of great interest was the energy barrier that keeps atoms on adjacent
carbyne chains from collapsing into each other. “When you’re talking about
theoretical material, you always need to be careful to see if it will react
with itself,” Artyukhov said. “This has never really been investigated for
carbyne.”
The
literature seemed to indicate carbyne “was not stable and would form graphite
or soot,” he said.
Instead,
the researchers found carbon atoms on separate strings might overcome the
barrier in one spot, but the rods’ stiffness would prevent them from coming
together in a second location, at least at room temperature. “They would look
like butterfly wings,” Artyukhov said.
“Bundles
might stick to each other, but they wouldn’t collapse completely,” Yakobson
added. “That could make for a highly porous, random net that may be good for
adsorption.” Artyukhov said the nominal specific area of carbyne is about five
times that of graphene.
When
the team’s paper became available this summer on arXiv, the scientific press and
even some of the popular press were so excited over the calculations that they
picked up on the paper and its implications before the team submitted it for
peer review. Now that the complete paper is ready for public consumption, the
researchers said they’ll carry their investigation in new directions.
They’re
taking a more rigorous look at the conductivity of carbyne and are thinking
about other elements as well. “We’ve talked about going through different
elements in the periodic table to see if some of them can form one-dimensional
chains,” Yakobson said.
Rice
graduate student Fangbo Xu and former postdoctoral researcher Hoonkyung Lee,
now a professor at Konkuk University in South Korea, are co-authors of the
paper. Yakobson is Rice’s Karl F. Hasselmann Professor of Mechanical
Engineering and Materials Science, a professor of chemistry and a member of the
Richard E. Smalley Institute for Nanoscale Science and Technology.
The
Air Force Office of Scientific Research and the Welch Foundation supported the
research. Calculations were performed on the National Science
Foundation-supported DaVinCI supercomputer,
administered by Rice’s Ken Kennedy Institute for
Information Technology.
Rice University
researchers have determined from first-principle calculations that carbyne
would be the strongest material yet discovered. The carbon-atom chains would be
difficult to make but would be twice as strong as two-dimensional graphene
sheets. (Credit: Vasilii Artyukhov/Rice University)
Nanoropes or nanorods
of carbyne, a chain of carbon atoms, would be stronger than graphene or even
diamond if they can be manufactured, according to new calculations by Rice
University. Theoretical physicist Boris Yakobson said the material might find
uses in electronics and for energy storage. (Credit: Vasilii Artyukhov/Rice
University)
Located on a 300-acre
forested campus in Houston, Rice University is consistently ranked among the
nation’s top 20 universities by U.S. News & World Report. Rice has highly
respected schools of Architecture, Business, Continuing Studies, Engineering,
Humanities, Music, Natural Sciences and Social Sciences and is home to the
Baker Institute for Public Policy. With 3,708 undergraduates and 2,374 graduate
students, Rice’s undergraduate student-to-faculty ratio is 6-to-1. Its
residential college system builds close-knit communities and lifelong
friendships, just one reason why Rice has been ranked No. 1 for best quality of
life multiple times by the Princeton Review and No. 2 for “best value” among
private universities by Kiplinger’s Personal Finance. To read “What they’re
saying about Rice,” go to http://tinyurl.com/AboutRiceU.
2 comments:
WILL YOU PLEASE... PLEASE! STOP POSTING IN ALL ITALICS ~ IT IS ALMOST IMPOSSIBLE TO READ!!!
(And yes I know I'm shouting. Italics on a computer screen are EXTREMELY hard to assimilate.)
As i have posted before, i use italics to separate imported material from my own writing. if necessary just go to the original source by the link
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