> > Scientists have announced they can now  make boron-nitride nanotube
> > yarn.  My question is ...... what are these yarns characteristics ?
> > Anyone know ?    I found nothing on gweegle.

Gargoyle says, after a few perms and coms, that this is the horse's mouth:

=A0=A0=A0 http://www.jlab.org/news/releases/2009/nanotube_yarn.html

Also, that this is the horse's spokeperson

=A0=A0=A0=A0=A0=A0=A0=A0 Contact: Kandice Carter, Jefferson Lab Public Affa=
irs,
757-269-7263, kcarter@jlab.org

from the following I'd hazard that the main gain is that they have
managed to produce materials at a size that can be combined into
arbitraily large sizes that exhibit the properties which are able to
be demonstrated in many nanotube structures at a microscopic level.
Often, materials which are eg theoretically immensey high strength do
not exhibit the target properties when produced in a macro scale.

____________

Key attributes sound or are said to be:

" ... first practical macroscopic yarns from boron nitride fibers,
opening the door for an array of applications, from radiation-shielded
spacecraft to stronger body armor, according to a just-published
study.

... high-quality ... highly crystalline and have a small diameter ...
structurally contain few walls and are very long ...

... Before, labs could make really good nanotubes that are are short
or really crummy ones that are long. We've developed a technique that
makes really good ones that are really long, ...

... the first high-quality BNNTs that are long enough to be spun into
macroscopic yarn, in this case centimeters long. A cotton-like mass of
nanotubes was finger-twisted into a yarn about one millimeter wide,
indicating that the nanotubes themselves are about one millimeter
long.

"They're big and fluffy, textile-like ...


... This means that you can use commercial textile manufacturing and
handling techniques to blend them into things like body armor and
solar cells and other applications."

... the nanotubes are very narrow, averaging a few microns in
diameter. TEM images also revealed that the BNNTs tended to be
few-walled, most commonly with two-five walls, although single-wall
nanotubes were also present. Each wall is a layer of material, and
fewer-walled nanotubes are the most sought after.

-- =

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