Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemist’s technique enables creation of novel carbon nanoparticles

11.05.2004


A technique developed by Karen Wooley has proved vital in the creation of novel carbon nanoparticles with colleagues at Carnegie Mellon University.


Wooley technique ’linchpin’ to success

Using a technique pioneered by Washington University in St. Louis chemist Karen Wooley, Ph.D., scientists have developed a novel way to make discrete carbon nanoparticles for electrical components used in industry and research.

The method uses polyacrylonitrile (PAN) as a nanoparticle precursor and is relatively low cost, simple and potentially scalable to commercial production levels. It provides significant advantages over existing technologies to make well-defined nanostructured carbons. Using the method, PAN copolymers serving as carbon precursors can be deposited as thin films on surfaces (for example, silicon wafers), where they can be patterned and further processed using techniques currently employed to fabricate microelectronic devices. Such a seamless manufacturing process is important to generate integrated devices and would be difficult to achieve with other methods currently used to synthesize nanostructured carbons, said Tomasz Kowalewski, Ph.D., assistant professor of chemistry at the Mellon College of Science and principal investigator on this research.



The research was presented March 28, 2004, at the 227th annual meeting of the American Chemical Society in Anaheim, Calif. The research findings have been accepted for publication in Angewandte Chemie, International Edition. The work was funded by the National Science Foundation.

The new approach is based on a method the Carnegie Mellon group previously developed to form nanostructured carbons by using block copolymers in which PAN is linked to other polymers with which it normally does not mix. In the current method, PAN, a water-hating compound, is copolymerized with polyacrylic acid, a water-loving polymer. In water-containing solutions, PAN-polyacrylic acid copolymers self assemble into nanoscale droplets, or micelles. Each micelle has a water-insoluble PAN core and a water-soluble polyacrylic acid outer coat that forms an outer shell.

The linchpin to make carbon nanoparticles from micelles is a shell-crosslinking technique that Wooley developed with Ph.D. student K. Bruce Thurmond II — now a research scientist at Access Pharmaceuticals, Dallas, Tex. — in the late 1990s at Washington University. Whereas polymer micelles are dynamic assemblies that can be reorganized or destroyed, the shell crosslinking technique allowed the Carnegie Mellon researchers to contain the PAN within the polyacrylic acid to maintain discrete nano-objects during manipulation of the materials. The scientists then deposited thin and ultra-thin films of these nanoparticles on various substrates. The Carnegie Mellon team heated the nanoparticles to high temperatures in a process called pyrolysis, decomposing the polyacrylic acid shell scaffolding and converting the chemically stabilized PAN domains into arrays of discrete carbon nanostructures.

"The preparation, manipulation and study of these highly interesting, discrete carbon nanoparticles were facilitated by an interdisciplinary collaboration that has involved the open sharing of knowledge, ideas, resources and researchers between several laboratories located at Washington University and Carnegie Mellon University," said Wooley. "This kind of cross-institutional teamwork provides for enhanced student experiences and allows for research accomplishments that would not ordinarily be possible, activities which have been supported in large part by the National Science Foundation."

"This work really illustrates a particularly attractive strategy in the evolution of nanotechnology," said Kowalewski, principal investigator on this research and a postdoctoral researcher at Washington University in the late 1990s, and long-time collaborator with Wooley. "Our well-defined carbon nanoparticles should find a wide range of applications, especially in energy storage/conversion devices and in display technologies."

The Carnegie Mellon group is currently working on using carbon nanoparticles as active materials in field emitter arrays for flat panel screen displays. This technology to produce carbon nanostructures also could be adapted to produce solar panels that convert sunlight into electrical energy. Other applications include the development of carbon-based nanosensors or high-surface area electrodes for use in biotechnology or medicine.

Tony Fitzpatrick | WUSTL
Further information:
http://news-info.wustl.edu/news/page/normal/848.html

More articles from Materials Sciences:

nachricht Researchers invent process to make sustainable rubber, plastics
25.04.2017 | University of Delaware

nachricht Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging
24.04.2017 | Pohang University of Science & Technology (POSTECH)

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>