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, one of Ajayan's current graduate students who came to Rensselaer from Tsinghua University.
Rensselaer Polytechnic Institute, founded in 1824, is the nation's oldest technological university. The school offers degrees in engineering, the sciences, information technology, architecture, management, and the humanities and social sciences. Institute programs serve undergraduates, graduate students, and working professionals around the world. Rensselaer faculty are known for pre-eminence in research and teaching. The Institute is especially well known for its success in the transfer of technology from the laboratory to the marketplace so that new discoveries and inventions benefit human life, protect the environment, and strengthen economic development.
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