Rice research yields 'designer' carbon nanotubes

April 08, 2002

HOUSTON--APRIL 8, 2002 -- Researchers at Rice University say fluorine -- the most reactive element in nature -- could prove to be a key in unlocking the potential of carbon nanotubes and other carbon nanostructures.

Rice chemists are presenting research at this week's annual meeting of the American Chemical Society in Orlando, Fla., that describes groundbreaking work in the fluorination of polyfullerenes, groupings of C-60 molecules that have been joined together in polymer chains and planes. Polyfullerenes are much more stable than organic polymers like polyethylene, polypropylene or nylon, and the addition of fluorine to the polyfullerenes could make it easier for chemists to use them in subsequent chemical reactions.

The Rice research is a collaboration with scientists at the Russian Academy of Science's Institute for High-pressure Physics near Moscow. The Russian researchers - Dr. V. A. Davydov and co-workers - created the polymeric fullerenes using a process involving temperatures up to 500º Celsius, and pressures up to 60,000 atmospheres. At Rice, researchers - Faculty Fellow Valery Khabashesku and Graduate Student Zhenning Gu - fluorinate the polyfullerenes, using techniques pioneered over the past three years in the fluorination of carbon nanotubes.

"Compared to other methods of forming derivatives of carbon nanostructures, fluorination leads to reactions that are more general in nature and more easily extrapolated to a macro or production scale," said John Margrave, Butcher Professor of Chemistry.

Since their discovery in 1991, scientists have speculated that carbon nanotubes could be used for everything from biological probes small enough to penetrate a living cell to wires in computer chips that are 100 times smaller than anything available with today's technology.

But carbon nanotubes are also inert and chemically stable, which has made it difficult for chemists to create nanotube derivatives -- tubes decorated with extra molecules that act as chemical "handles" for further manipulation. Most processes that laboratory researchers have used to create nanotube derivatives are impractical on a macro scale because they involve the use of extremely high temperatures, high pressures or other techniques that are difficult to reproduce in a production setting.

Fluorine, which is often shunned by chemists because of its highly reactive nature, has proven to be very useful as an alternative means of creating nanotube derivatives, precisely for that reason. The addition of fluorine opens the door to subsequent chemical reactions, giving chemists the ability to attach other types of molecules to nanotubes.

So far, Margrave and his colleagues have used this process to create dozens of "designer" nanotube derivatives. These include hydrotubes, which contain hydrogen in an activated form; hexyl nanotubes, methoxy nanotubes, amido nanotubes, and other varieties containing organic side chains; polymers similar to nylon; and hydrogen-bonded nylon analogs. Unlike pure carbon nanotubes, all these derivatives are soluble in traditional organic solvents.

Potential applications for the nanotube derivatives are still being identified, but hydrotubes, which contain hydrogen in an activated form, might find a use as an ultra efficient fuel, and silicate-coated nanotubes could be used in nanoscale electronic devices.
-end-
Margrave's work is sponsored by grants from the Welch Foundation and the Texas Advanced Technology Program.

Rice University

Related Carbon Nanotubes Articles from Brightsurf:

How plantains and carbon nanotubes can improve cars
Researchers from the University of Johannesburg have shown that plantain, a starchy type of banana, is a promising renewable source for an emerging type of lighter, rust-free composite materials for the automotive industry.

New production method for carbon nanotubes gets green light
A new method of producing carbon nanotubes -- tiny molecules with incredible physical properties used in touchscreen displays, 5G networks and flexible electronics -- has been given the green light by researchers, meaning work in this crucial field can continue.

Growing carbon nanotubes with the right twist
Researchers synthetize nanotubes with a specific structure expanding previous theories on carbon nanotube growth.

Research shows old newspapers can be used to grow carbon nanotubes
New research has found that old newspaper provide a cheap and green solution for the bulk production of single walled carbon nanotubes.

Clean carbon nanotubes with superb properties
Scientists at Aalto University, Finland, and Nagoya University, Japan, have found a new way to make ultra-clean carbon nanotube transistors with superior semiconducting properties.

Dietary fiber effectively purifies carbon nanotubes
A dietary fiber can help separate out semiconducting carbon nanotubes used for making transistors for flexible electronics.

Why modified carbon nanotubes can help the reproducibility problem
Scientists at Tokyo Institute of Technology (Tokyo Tech) conducted an in-depth study on how carbon nanotubes with oxygen-containing groups can be used to greatly enhance the performance of perovskite solar cells.

Tensile strength of carbon nanotubes depends on their chiral structures
Single-walled carbon nanotubes should theoretically be extremely strong, but it remains unclear why their experimental tensile strengths are lower and vary among nanotubes.

New study reveals carbon nanotubes measurement possible for the first time
Swansea University scientists report an entirely new approach to manipulation of carbon nanotubes that allows physical measurements to be made on carbon nanotubes that have previously only been possible by theoretical computation.

Neural networks will help manufacture carbon nanotubes
A team of scientists from Skoltech's Laboratory of Nanomaterials proposed a neural-network-based method for monitoring the growth of carbon nanotubes, preparing the ground for a new generation of sophisticated electronic devices.

Read More: Carbon Nanotubes News and Carbon Nanotubes Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.