> On Sat, 1 Mar 1997, Carl Feynman/Forrest Bishop wrote:
> [...]
> > >"Graphite Fiber")
> >
> > It's a fiber consisting of pure graphite, i.e. carbon. How is this a misnomer?
> >
> > [[As I understand it, Carbon Fiber come in different grades, and is made by pyrolyzing
> > various polymeric hydrocarbons, like rayon or nylon. The resulting fiber is (*I think*)
> > a mixed up conglomeration of sp2 and sp3 hybrid bonds. Maybe it is mostly graphitic-
> > I'll put that aside aside.]]
> Buckyballs are easy to spot, but what are buckytubes? I don't think
> one can call them graphite, since curvature of the concentric sheets is
> quite large.
...
> I don't know how the bucky tubes are produced. At a guess, grown from
> gas phase, using transition metal (nickel?) catalysis?
See
http://cnst.rice.edu/aiche96.html
which is the transcript of a lecture by Smalley (Nobel prize winner)
on buckytubes. His team can make bundles of single-walled carbon
nanotubes (SWNTs) by laser vaporization of graphite + about 1%
nickel or nickel/cobalt in a 1200 C oven. Yields of SWNTs exceed
70%. The tensile strength of these SWNTs is infered to be greater than
diamond; these tubes are easily strong enough to build Clarke's
geostationary elevator with little or no taper. The tubes are
essentially perfect (any defect causes the tube to pinch off) and
they self-assemble into hexagonally packed "ropes".
Lots of other interesting papers are available from cnst.rice.edu; do
a web search.
Paul