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:3/28/2017)... ... ... Franz Inc ., the leading supplier of Semantic Graph Database technology, ... by Bloor Research in its recent Graph Database Market Update report. ... Gruff, it was rated as the easiest product to use.” – Bloor Research , ...
(Date:3/28/2017)... (PRWEB) , ... March 28, 2017 , ... ... time members of the Modular Building Institute (MBI), an international modular trade organization, ... the permanent modular category for the Pagliuca Life Lab at Harvard University. The ...
(Date:3/28/2017)... , Belgium , March 28, 2017 ... VolitionRx Limited (NYSE MKT: VNRX), today announced the engagement of ... DVD Associates, LLC, as a strategic consultant. Dr. Vollmer ... identifying and securing non-dilutive funding in the State ... United States . Dr. Vollmer Dahlke has ...
(Date:3/28/2017)... SACRAMENTO, Calif. , March 28, 2017 /PRNewswire/ ... Officer of international life sciences corporation Anpac ... company set a new, international record, processing and ... proprietary, "Cancer Differentiation Analysis" (CDA) liquid ... in World Nobel Prize Laureate Summit publications, Anpac ...
Breaking Biology Technology:
(Date:2/28/2017)... 27. Februar 2017  EyeLock LLC, ein marktführendes Unternehmen ... erstklassige biometrische Lösung zur Iris-Erkennung auf der ... LTE auf dem Mobile World Congress 2017 ... in Halle 3, Stand 3E10, vorstellen. ... Qualcomm Haven™ – eine Kombination aus Hardware, ...
(Date:2/24/2017)...  EyeLock LLC, a leader of iris-based identity ... biometric solution on the latest Qualcomm® Snapdragon™ 835 ... World Congress 2017 (February 27 – March ... 3, Stand 3E10. The Snapdragon ... platform—a combination of hardware, software and biometrics ...
(Date:2/21/2017)... Der weltweite Biobanking-Sektor wird bis zum Jahr 2018 ... mehr als 50 Vertretern aus verschiedenen Branchen wurde aber klar, ... Prognose zu realisieren. ... Zu den Schwierigkeiten für Biobanking-Profis ... die Biobank, die Implementierung Zeit sparender Technologien, ein besseres ...
Breaking Biology News(10 mins):