 |
|
Method could help carbon nanotubes become commercially viable
October 05, 2006EVANSTON, Ill. - Carbon nanotubes are intriguing new materials which have been highly touted for their exceptional mechanical, thermal, optical and electrical properties.
Researchers worldwide are striving to apply these nanostructures in electronics, high-resolution displays, high-strength composites and biosensors. A fundamental problem relating to their synthesis, however, has limited their widespread use.
Current methods for synthesizing carbon nanotubes produce mixtures of tubes that differ in their diameter and twist. Variations in electronic properties arise from these structural differences, resulting in carbon nanotubes that are unsuitable for most proposed applications.
Now, a new method developed at Northwestern University for sorting single-walled carbon nanotubes promises to overcome this problem. The method works by exploiting subtle differences in the buoyant densities of carbon nanotubes as a function of their size and electronic behavior. The results will be published online Wednesday, Oct. 4, in the inaugural issue of the journal Nature Nanotechnology (October 2006).
"Carbon nanotubes, because of their ultra-small size and excellent materials properties, have excited the scientific community for the last decade," said Mark Hersam, professor of materials science and engineering at Northwestern's McCormick School of Engineering and Applied Science, who led the research team.
"However, due to their inherent heterogeneity, they have not yet realized their full commercial potential," he said. "A scalable and economical method for producing monodisperse carbon nanotubes will enable the proposed applications for these nanomaterials to be explored at an industrially relevant scale."
Using the Northwestern method, carbon nanotubes first are encapsulated in water by soap-like molecules called surfactants. Next, the surfactant-coated nanotubes are sorted in density gradients which are spun at tens of thousands of rotations per minute in an ultracentrifuge. By carefully choosing the surfactants utilized during ultracentrifugation, the researchers found that carbon nanotubes could be sorted by diameter and electronic structure.
As a part of their study, the researchers demonstrated the fabrication of electrical devices that displayed either semiconducting or metallic behavior, depending on the sorted nanotubes used. The researchers also maintain that their technique can be translated to an industrial scale.
"The technique is especially promising for commercial applications," said Hersam, "because large-scale ultracentrifuges have already been developed and shown to be economically viable in the pharmaceutical industry. We anticipate that this precedent can be straightforwardly translated to the production of monodisperse carbon nanotubes."
Northwestern University
Now, a new method developed at Northwestern University for sorting single-walled carbon nanotubes promises to overcome this problem. The method works by exploiting subtle differences in the buoyant densities of carbon nanotubes as a function of their size and electronic behavior. The results will be published online Wednesday, Oct. 4, in the inaugural issue of the journal Nature Nanotechnology (October 2006).
"Carbon nanotubes, because of their ultra-small size and excellent materials properties, have excited the scientific community for the last decade," said Mark Hersam, professor of materials science and engineering at Northwestern's McCormick School of Engineering and Applied Science, who led the research team.
"However, due to their inherent heterogeneity, they have not yet realized their full commercial potential," he said. "A scalable and economical method for producing monodisperse carbon nanotubes will enable the proposed applications for these nanomaterials to be explored at an industrially relevant scale."
Using the Northwestern method, carbon nanotubes first are encapsulated in water by soap-like molecules called surfactants. Next, the surfactant-coated nanotubes are sorted in density gradients which are spun at tens of thousands of rotations per minute in an ultracentrifuge. By carefully choosing the surfactants utilized during ultracentrifugation, the researchers found that carbon nanotubes could be sorted by diameter and electronic structure.
As a part of their study, the researchers demonstrated the fabrication of electrical devices that displayed either semiconducting or metallic behavior, depending on the sorted nanotubes used. The researchers also maintain that their technique can be translated to an industrial scale.
"The technique is especially promising for commercial applications," said Hersam, "because large-scale ultracentrifuges have already been developed and shown to be economically viable in the pharmaceutical industry. We anticipate that this precedent can be straightforwardly translated to the production of monodisperse carbon nanotubes."
Northwestern University
Carbon Nanotubes Current Events and Carbon Nanotubes News RSSCaltech scientists develop DNA origami nanoscale breadboards for carbon nanotube circuits
In work that someday may lead to the development of novel types of nanoscale electronic devices, an interdisciplinary team of researchers at the California Institute of Technology (Caltech) has combined DNA's talent for self-assembly with the remarkable electronic properties of carbon nanotubes, thereby suggesting a solution to the long-standing problem of organizing carbon nanotubes into nanoscale electronic circuits.
Breakthrough in industrial-scale nanotube processing
Rice University scientists today unveiled a method for the industrial-scale processing of pure carbon-nanotube fibers that could lead to revolutionary advances in materials science, power distribution and nanoelectronics.
Next-generation microcapsules deliver 'chemicals on demand'
Scientists in California are reporting development of a new generation of the microcapsules used in carbon-free copy paper, in which capsules burst and release ink with pressure from a pen.
Study shows how carbon nanotubes can affect lining of the lungs
Carbon nanotubes are being considered for use in everything from sports equipment to medical applications, but a great deal remains unknown about whether these materials cause respiratory or other health problems.
Advance in 'nano-agriculture': Tiny stuff has huge effect on plant growth
With potential adverse health and environmental effects often in the news about nanotechnology, scientists in Arkansas are reporting that carbon nanotubes (CNTs) could have beneficial effects in agriculture.
A recipe for controlling carbon nanotubes
Nanoscopic tubes made of a lattice of carbon just a single atom deep hold promise for delivering medicines directly to a tumor, sensors so keen they detect the arrival or departure of a single electron, a replacement for costly platinum in fuel cells or as energy‐saving transistors and wires.
Friction force differences could offer a new means for sorting and assembling nanotubes
Nanotubes and nanowires are promising building blocks for future integrated nanoelectronic and photonic circuits, nanosensors, interconnects and electro-mechanical nanodevices. But some fundamental issues remain to be resolved - among them, how to position and manipulate the tiny tubes.
New biosensor can detect bacteria instantaneously
A research group from the Rovira i Virgili University (URV) in Tarragona has developed a biosensor that can immediately detect very low levels of Salmonella typhi, the bacteria that causes typhoid fever.
Researchers design new graphene-based, nano-material with magnetic properties
An international team of researchers has designed a new graphite-based, magnetic nano-material that acts as a semiconductor and could help material scientists create the next generation of electronic devices like microchips.
Researchers Pinpoint Neural Nanoblockers in Carbon Nanotubes
A team of Brown University scientists has pinpointed why carbon nanotubes tend to block a critical signaling pathway in neurons.
More Carbon Nanotubes Current Events and Carbon Nanotubes News Articles
 |
Carbon Nanotube Science: Synthesis, Properties and Applications by Peter J. F. Harris (Author) Carbon nanotubes represent one of the most exciting research areas in modern science. These molecular-scale carbon tubes are the stiffest and strongest fibres known, with remarkable electronic properties, and potential applications in a wide range of fields. Carbon Nanotube Science is the most concise, accessible book for the field, presenting the basic knowledge that graduates and researchers need to know. Based on the successful Carbon Nanotubes and Related Structures, this new book focuses solely on carbon nanotubes, covering the major advances made in recent years in this rapidly developing field. Chapters focus on electronic properties, chemical and bimolecular functionalisation, nanotube composites and nanotube-based probes and sensors. The book begins with a comprehensive... |
 |
Carbon Nanotubes: Properties and Applications by Michael J. O'Connell (Editor) Since their discovery more than a decade ago, carbon nanotubes (CNTs) have held scientists and engineers in captive fascination, seated on the verge of enormous breakthroughs in areas such as medicine, electronics, and materials science, to name but a few. Taking a broad look at CNTs and the tools used to study them, Carbon Nanotubes: Properties and Applications comprises the efforts of leading nanotube researchers led by Michael O’Connell, protégé of the late father of nanotechnology, Richard Smalley. Each chapter is a self-contained treatise on various aspects of CNT synthesis, characterization, modification, and applications. The book opens with a general introduction to the basic characteristics and the history of CNTs, followed by discussions on synthesis methods and the... |
 |
Easton MonkeyLite XC CNT Carbon Fiber MTB Riser Bicycle Handlebar (660mm Wide, 40mm Rise) by Easton Low and high rise (8° sweep | 4° upsweep) |
 |
Carbon Nanotubes: Advanced Topics in the Synthesis, Structure, Properties and Applications (Topics in Applied Physics) by Ado Jorio (Author), Ado Jorio (Editor), Gene Dresselhaus (Editor), Mildred S. Dresselhaus (Editor) The carbon nanotubes field has evolved substantially since the publication of the bestseller Carbon Nanotubes: Synthesis, Structure, Properties and Applications . The present volume builds on the generic aspects of the aforementioned book, which emphasizes the fundamentals, with the new volume emphasizing areas that have grown rapidly since the first volume, guiding future directions where research is needed and highlighting applications. The volume also includes an emphasis on areas like graphene, other carbon-like and other tube-like materials because these fields are likely to affect and influence developments in nanotubes in the next 5 years. |
 |
Carbon Nanotubes: Basic Concepts and Physical Properties by Stephanie Reich (Author), Christian Thomsen (Author), Janina Maultzsch (Author) Carbon nanotubes are exceptionally interesting from a fundamental research point of view. Many concepts of one-dimensional physics have been verified experimentally such as electron and phonon confinement or the one-dimensional singularities in the density of states; other 1D signatures are still under debate, such as Luttinger-liquid behavior. Carbon nanotubes are chemically stable, mechanically very strong, and conduct electricity. For this reason, they open up new perspectives for various applications, such as nano-transistors in circuits, field-emission displays, artificial muscles, or added reinforcements in alloys. This text is an introduction to the physical concepts needed for investigating carbon nanotubes and other one-dimensional solid-state systems. Written for... |
|
|
Easton MonkeyLite SL CNT Carbon Fiber MTB Riser Bicycle Handlebar (31.8mm Diameter, 635mm Wide, 20mm Rise) by Easton New carbon unidirectional design |
 |
Carbon Nanotubes: Synthesis, Structure, Properties and Applications by et al R.E. Smalley (Foreword) (Author) This book gives a comprehensive review of the present status of research in this fast moving field by researchers actively contributing to the advances. After a short introduction and a brief review of the relation between carbon nanotubes, graphite and other forms of carbon, the synthesis techniques and growth mechanisms for carbon nanotubes are described. This is followed by reviews on nanotube electronic structure, electrical, optical, and mechanical properties, nanotube imaging and spectroscopy, and nanotube applications. |
 |
Physical Properties of Carbon Nanotubes by R. Saito (Author) This text is intended for researchers who want to perform theoretical analysis of carbon nanotubes. It can be used by graduate students in a solid state physics to learn how to investigate the structure of carbon nanotubes, its electronic and vibrational properties. |
|
|
Easton MonkeyLite XC CNT Carbon Fiber MTB Riser Bicycle Handlebar (685mm Wide, 40mm Rise) by Easton Low and high rise (8° sweep | 4° upsweep) |
 |
Understanding Carbon Nanotubes: From Basics to Applications (Lecture Notes in Physics) by A. Loiseau (Editor), P. Launois (Editor), P. Petit (Editor), S. Roche (Editor), J.-P. Salvetat (Editor) This volume presents the foundations of carbon nanotube science including the most recent developments and the prospects for technological applications. Each chapter begins with a tutorial introduction to the relevant interdisciplinary topics from physics, chemistry or materials science. These summaries of the essential background knowledge are followed by detailed presentations of specific issues. The latter include: polymorphism of carbon and the microstructure of its phases; synthesis methods and growth mechanisms; structural analysis by electron microscopy; spectroscopic methods; electronic structure; transport; mechanical and surface properties of nanotubes and composites. All readers, be they students or experienced researchers, will come to appreciate how progress in nanotube... |
| © 2009 BrightSurf.com |