May 2, 2002
Troy, N.Y. — For the first time, researchers have created a
simplified method for making long, continuous, hair-like
strands of carbon nanotubes that are as much as eight inches in
length. This breakthrough, reported in the May 3 issue of
Science, is a first step toward creating such products as
microcables for electrical devices or mechanically robust
electrochemical actuators for artificial muscles.
The researchers from Rensselaer Polytechnic Institute and
collaborators at Tsinghua University in Beijing found that
chemical vapor deposition (CVD), a widely used technique to
grow nanotubes, has a high yield of long strands when a
sulfur-containing compound and hydrogen are added to the
process.
Researchers have previously created nanotube fibers with more
complex methods, but because CVD is commonly used to make
nanotubes, it would be easily adaptable and more efficient for
synthesizing the long strands for practical applications.
This new method produced nanotubes that measured 20
centimeters, much longer than conventional nanotubes, said
Pulickel Ajayan.
“Carbon nanotubes are generally microns in length, which is
not long enough for any practical purpose,” said Ajayan,
associate professor of materials science at Rensselaer
Polytechnic Institute in Troy, N.Y. “We have created strands
with nearly aligned nanotubes that are as long as 20
centimeters. The nanotubes are well ordered in these structures
and are self-assembled during the growth process, which means
we don’t end up with an unusable lump that looks like cooked
spaghetti,” he added.
The process could also be an easier alternative to creating
high-purity single-walled nanotube material in general, said
Bingqing Wei, a post doctoral associate of Ajayan’s who came to
Rensselaer from Tsinghua University.
Contact: Bruce Adams
Phone: (518) 276-6531
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