Graphene

Sat Jan 12 11:46:19 CST 2013

What Prashant said. As quantum theory emerged a century ago, we were struck
by its "weirdness": entities, properties and behaviors very different from,
even  flatly contradictory to,  those of the macroscopic sensory world. At
the same time, physicists knew that somehow the e, p and b we know must be
consistent with and built up out of the quantum e, p and b. Some of that
building-up is just statistics: a thin layer of glass or rubber is still an
insulator for all technological purposes even if quantum mechanics shows
that one in 10-to-the-umpteenth-power electrons "tunnels" right through it.
We came late to the weirdness because it's almost always smeared out,
averaged away, drowned out, over the quintillions of atoms/molecules in even
the tiniest amount of stuff - "condensed matter," not hot sodium atoms
floating alone in near-vacuum or electrons streaming through a CRT - that we
typically work with.

All sorts of things happen in the many orders of magnitude between quantum
and everyday phenomena. For one, the engineering materials we work with are
typically much weaker than would be expected from the strength of the
chemical (= electric charge = quantum-mechanical) bonds between their atoms
and molecules. Look at the scales in between, and the purest metal, the most
perfect-looking crystal, is shot through with flaws, dislocations,  grain
boundaries: places where the quantum-level bonds are interrupted. So the
bulk material's strength (and conductivity and other bond-dependent
properties) typically reflect those "weakest link" numbers, not the
atom-to-atom properties.

What makes graphene, carbon nanotubes, and buckyballs special is that
physics and experimental craft combine to make them damn near perfect. The
sp2 bond between two carbon atoms is already very strong as interatomic
bonds go; with the right conditions and catalysts, hot carbon atoms flying
around in a reaction vessel are far more likely to form that bond over and
over and over in a hexagonal chicken-wire pattern than any other: one
perfect bond after another extending over huge numbers of atoms- rolled into
spheres for buckyballs, into cylinders as nanotubes, or spread out in sheets
as graphene. They can have not only macroscopic-scale strength approaching
the strength of the carbon bonds, but other quantum-mechanical properties -
some of them weird -- "writ large." (Very important caveat: as Prashant sez,
it can take decades to turn lab-scale capabilities into affordable
industrial-scale production. Everything a transistor does was implicit in
the physics of 1925, but we didn't make the first one until the late 1940s,
and it decades and billion$ more to Intel Everygoddamnwhere.)   

We trawl down into rigorous, invisible, weird perfection and drag it up into
our loveable, scatterbrained world: too late for TRP, but someday some
writer will do with all this what he has done with late-19th-century
chemistry, electromagnetism and math. Not that it matters -- as Alice will
doubtless assure us, it's the merest scrimshaw.  

From: owner-pynchon-l at waste.org [mailto:owner-pynchon-l at waste.org] On Behalf
Of Prashant Kumar
Sent: Friday, January 11, 2013 8:31 PM
To: rich
Cc: "pynchon-l at waste.org"
Subject: Re: Graphene

That's right. The only way we would be able to build such a thing, by
layering graphene sheets over graphene sheets, would just give us graphite -
the stuff in a pencil. Most of the technological and physical properties
result from the fact that graphene is a single layer of carbon atoms. 

Now, given magic/aliens, we could imagine wrapping up these graphene sheets
- into carbon nanotubes - and putting them together into a pencil. But even
then, we would see changes in electronic properties. This, by the way, is a
dream of condensed matter physics -- programmable matter. 

http://en.wikipedia.org/wiki/Programmable_matter

P. 

On Saturday, 12 January 2013, rich wrote:

The media does seem to overblow scientific breakthroughs so-called.

dumb question: are you saying scaling graphene would essentially
change it into something that isn't graphene anymore or does not have
the same physical properties? sorry, the only chemistry I've learned
in the last decade is from watching Breaking Bad ;)

rich

On Thu, Jan 10, 2013 at 8:36 PM, Prashant Kumar
<siva.prashant.kumar at gmail.com <javascript:;> > wrote:
> Unfortunately the elephant-pencil thing (in SciAm, right?) thing is
somewhat
> specious, in that "graphene" as thick as a pencil is just graphite.
> Alien-tech-level methods of fabricating such a thing notwithstanding,
> scaling up the mechanical properties of graphene in such a way would
result
> in changes in physical structure which would nullify the technological
> applications.
>
> P.
>
> On Friday, 11 January 2013, rich wrote:
>>
>> thanks man
>>
>> I need a science guy to help me out. I did like the elephant and
>> pencil analogy. guess graphene replacing silicon is many years away.
>>
>> rich
>>
>> On Wed, Jan 9, 2013 at 9:32 PM, Prashant Kumar
>> <siva.prashant.kumar at gmail.com <javascript:;> > wrote:
>> > For those who don't know, graphene is basically a single-atom thick
>> > layer of
>> > graphite with some very interesting physical properties. Basically,
>> > under
>> > certain conditions, you can force the charge carriers, erstwhile
>> > electrons,
>> > to behave as different kinds of particles, which results in a range of
>> > physically and technologically interesting phenomena.
>> >
>> > I  would argue that, all things considered, graphene is not bleeding
>> > edge;
>> > more properly emerging. It's not a technology in the sense a layman
>> > would
>> > recognise: it's reasonably far away from commercial application.
Problem
>> > is
>> > with fabrication of suitable samples. The guys at Manchester who won
the
>> > Nobel in Physics last year used what's now called the "Scotch tape"
>> > method.
>> > You get a sample of graphite and "exfoliate" (read stick it on and then
>> > peel
>> > it off) a layer of graphene. This is one of the most efficient methods
>> > known. However, graphene in this state is brittle, so there's problems
>> > scaling up.  Many of the really cool things you can do right now have
>> > also
>> > been demonstrated in other materials.
>> >
>> > Graphene electronics proper is I think maybe a decade or so away. Even
>> > then
>> > I think deployment of graphene will be in concert with other tech, most
>> > exciting of which is perhaps "spintronics". If an electron is spinning
>> > clockwise, it has spin down, anticlockwise, spin up. The idea is you
run
>> > circuits using spin information. This allows for very interesting
>> > circuits,
>> > where information can flow both ways along a single line. Cool think
>> > about
>> > graphene here is that it exhibits such effects at room temperature,
>> > where
>> > every other material needs superconducting (~1-2K) temperatures, which
>> > limits commercial utility.
>> >
>> > P.
>> >
>> > On 8 January 2013 07:00, rich <richard.romeo at gmail.com <javascript:;> >
wrote:
>> >>
>> >> the "new plastic".
>> >> for those better equipped to explian it would u consider graphene a
>> >> potential bleeding edge technology?
>> >
>> >

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