Open menu

Nanotechnology Spotlight

Behind the buzz and beyond the hype:
Our Nanowerk-exclusive feature articles

RSS Subscribe to our Nanotechnology Spotlight feed

Showing Spotlights 257 - 264 of 285 in category Carbon Nanotubes (newest first):

 

The challenge of separating and sorting carbon nanotubes after production

Current production methods for carbon nanotubes result in units with different diameter, length, chirality and electronic properties, all packed together in bundles, and often blended with some amount of amorphous carbon. The separation of nanotubes according to desired properties remains a technical challenge. Especially single-walled carbon nanotube (SWCNT) sorting is a challenge because the composition and chemical properties of SWCNTs of different types are very similar, making conventional separation techniques inefficient.

Posted: Aug 21st, 2006

Quantum dot nanodevices with carbon nanotubes

Carbon nanotubes are attractive materials as the building block of quantum-dot based nanodevices. In particular, single-wall carbon nanotubes (SWCNTs) are interesting because they become metallic and semiconducting, depending on how they are rolled up from the graphene sheet, and they could be applied to various devices such as ultrasmall field-effect transistors, single-electron devices, quantum computing devices, and light-emitting devices. A research group at the Japanese Institute of Physical and Chemical Research (RIKEN) has made extensive experimental efforts to apply SWCNTs to single-electron devices and quantum computing devices (spin qubit) with a single quantum dot as a basic structure.

Posted: Aug 4th, 2006

Discovery of new structural evolution of carbon nanotubes

Researchers at the University of Sydney have revealed a new structural evolution of carbon nanotubes (CNTs) in epoxy composites during contact sliding and have shown that the evolution has three stages which are a) the bonding breakage of the CNTs, b) the formation of sinusoidal shells, and c) the consolidation of nanoparticles. This may present a potentially effective way to obtain nanoparticles with controlled structure and size.

Posted: Jul 21st, 2006

Carbon nanotube nanothermometers

The oxidation-assisted temperature measurement with carbon nanotube nanothermometers that contain liquid gallium is a novel and reliable method that can be used over a moderate temperature range and can be applied in any environment where air is present. All the other available techniques that are capable to measure temperature at the nanometer scale are limited by either that they are only workable in a very narrow temperature range or that they can only be applied in a special environment.

Posted: Jul 20th, 2006

Building optical molecular probes with nanotubes

Researchers in South Korea used single-walled carbon nanotubes (SWNTs) to tag single-stranded DNA to locate a particular sequence of DNA within a complex genome. The results show that SWNTs may be used as generic nano-biomarkers for the precise detection of specific kinds of genes.

Posted: Jul 18th, 2006

A new concept for compound nanotube fabrication

A new method based on the nanoscale Kirkendall effect was demonstrated to fabricate compound nanotubes. Through a spinel-forming solid-state reaction, high aspect-ratio core-shell ZnO-Al2O3 nanowires transform into monocrystalline ZnAl2O4 nanotubes.

Posted: Jul 14th, 2006

A novel method for mass production of nanotube based electronics

The mass production of nanoelectronic devices has been hampered by difficulties in aligning and integrating the millions of nanotubes required for the job. Now, researchers in South Korea have developed a method to precisely assemble and align single-walled carbon nanotubes (SWCNTs) onto solid substrates without relying on external forces such as electric or magnetic fields. This result could be an important guideline for the large-scale directed-assembly of integrated devices based on SWCNTs.

Posted: Jul 5th, 2006