Navigation Links
A recipe for controlling carbon nanotubes
Date:9/20/2009

CLEVELAND 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.

Single‐walled carbon nanotubes, made of a cheap and abundant material, have so much potential because their function changes when their atomic‐level structure, referred to as chirality, changes.

But for all their promise, building tubes with the right structure has proven a challenge.

A pair of Case Western Reserve University researchers mixed metals commonly used to grow nanotubes and found that the composition of the catalyst can control the chirality.

In a letter to be published Sept. 20 in the online edition of Nature Materials, R. Mohan Sankaran, an assistant professor of chemical engineering at the Case School of Engineering, and Wei‐Hung Chiang, who received his doctorate degree in chemical engineering in May, describe their findings.

"We have established a link between the structure of a catalyst and the chirality of carbon nanotubes," Sankaran said. "Change the catalyst structure by varying its composition, and you can begin to control the chirality of the nanotubes and their electrical and optical properties."

The chirality of a single‐walled carbon nanotube describes how a lattice of carbon atoms is rolled into a tube. The rolling can occur at different angles, producing different structures that exhibit very different properties.

Nanotubes are normally grown in bulk mixtures. When using a nickel catalyst, typically one‐third of those grown are metallic and could be used like metal wires to conduct electricity. About two‐thirds are semiconducting nanotubes, which could be used as transistors, Chiang explained. But, separating them according to properties, "is costly and can damage the nanotubes."

Better to make what you want.

Chiang and Sankaran found that a mixed iron and nickel catalyst could change the outcome. Of the compositions tested, a catalyst of 27 percent nickel and 73 percent iron produced the most dramatic result: the vast majority of the nanotubes were semiconducting. They are now working on assessing the purity and integrating the nanotubes into thin film transistors.

The authors say their findings open the door to experimenting with other elements as catalysts and different combinations, which may produce near‐pure nanotubes with desired properties.


'/>"/>

Contact: Kevin Mayhood
kevin.mayhood@case.edu
216-534-7183
Case Western Reserve University
Source:Eurekalert

Related biology technology :

1. China Biologic Products Completes Acquisition of 90% Controlling Interest in Chongqing Dalin Biologic Technologies Co., Ltd.
2. Light-speed nanotech: Controlling the nature of graphene
3. China Biologic Products Enters Into Agreement to Acquire 90% Controlling Interest in Chongqing Dalin Biologic Technologies Co., Ltd.
4. Controlling the size of nanoclusters
5. Light touch: Controlling the behavior of quantum dots
6. Controlling the size of nanoclusters: First step in making new catalysts
7. ProMetic to obtain controlling stake in Pathogen Removal and Diagnostic Technologies Inc.
8. Gladstone scientists identify role of tiny RNAs in controlling stem cell fate
9. Halocarbon Announces Licensing Agreement with IBM
10. Biopolymers Symposium 2009 Teams with Carbonfund.org to Create a Zero-Carbon Event
11. Ricardo Launches Consortium to Evaluate Lubricant Challenges of Future Low Carbon Engine Technologies
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/9/2016)... /PRNewswire/ - Portage Biotech Inc. ("Portage" or "the Company") ... announce that Biohaven has issued today the following press ... (PRWEB) Dec 9, 2016 - Biohaven Pharmaceutical Holding ... the U.S. Food and Drug Administration ("FDA") has granted ... candidate BHV-0223, an orally dissolving tablet being developed for ...
(Date:12/8/2016)... -- OncoSec Medical Incorporated ("OncoSec") (NASDAQ: ONCS ... today announced financial results for the fiscal first ... on our commitment to address an unmet medical ... pleased with the early clinical response data presented ... focused on advancing our lead program – ImmunoPulse® ...
(Date:12/8/2016)... , Dec. 8, 2016 Eurofins announces the appointment ... and President of Eurofins Scientific Inc. (ESI). Mr. ... his proven professional and entrepreneurial experience in leading international business teams. ... US food testing market to uphold Eurofins, status as the global ... ...
(Date:12/8/2016)... BARCELONA, Spain , Dec. 8, 2016  Anaconda ... on the development of the next generation neuro-thrombectomy system ... the appointment of Tudor G. Jovin, MD to join ... to serve as a strategic network of scientific and ... progresses the development of the ANCD BRAIN ® ...
Breaking Biology Technology:
(Date:11/22/2016)... 2016 According to the new market research report ... Vein, Signature, Voice), Multi-Factor), Component (Hardware and Software), Function (Contact and Non-contact), ... market is expected to grow from USD 10.74 Billion in 2015 to ... 2016 and 2022. Continue Reading ... ...
(Date:11/21/2016)...   Neurotechnology , a provider of high-precision ... that the MegaMatcher On Card fingerprint matching algorithm ... NIST Minutiae Interoperability Exchange (MINEX) III ... of the evaluation protocol. The ... fingerprint templates used to establish compliance of template ...
(Date:11/17/2016)... -- Global Market Watch: Primarily supported by ownership ... and Academics) market is to witness a value of US$37.1 ... highest Compounded Annual Growth Rate (CAGR) of 10.75% is foreseen ... period 2014-2020. North America is not ... Europe at 9.56% respectively. Report Focus: ...
Breaking Biology News(10 mins):