Navigation Links
A recipe for controlling carbon nanotubes

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
Case Western Reserve University

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 to Create a Zero-Carbon Event
11. Ricardo Launches Consortium to Evaluate Lubricant Challenges of Future Low Carbon Engine Technologies
Post Your Comments:
(Date:10/11/2017)... ... October 11, 2017 , ... ... it will be hosting a Webinar titled, “Pathology is going digital. Is your ... on digital pathology adoption best practices and how Proscia improves lab economics and ...
(Date:10/11/2017)... ROTTERDAM, the Netherlands and LAGUNA HILLS, ... that The Institute of Cancer Research, London ... will use MMprofilerâ„¢ with SKY92, SkylineDx,s prognostic tool to risk-stratify ... high-risk trial known as MUK nine . The University ... this trial, which is partly funded by Myeloma UK, and ...
(Date:10/11/2017)... ... October 11, 2017 , ... ... implantation and pregnancy rates in frozen and fresh in vitro fertilization (IVF) ... and maternal age to IVF success. , After comparing the results from the ...
(Date:10/10/2017)... , ... October 10, 2017 , ... San Diego-based team ... its corporate rebranding initiative announced today. The bold new look is part of ... the company moves into a significant growth period. , It will also expand its ...
Breaking Biology Technology:
(Date:3/30/2017)... March 30, 2017  On April 6-7, 2017, ... Genome hackathon at Microsoft,s headquarters in ... will focus on developing health and wellness apps that ... Hack the Genome is the first hackathon for ... world,s largest companies in the genomics, tech and health ...
(Date:3/28/2017)... , March 28, 2017 ... Biometrics), Hardware (Camera, Monitors, Servers, Storage Devices), Software (Video ... and Region - Global Forecast to 2022", published by ... in 2016 and is projected to reach USD 75.64 ... 2017 and 2022. The base year considered for the ...
(Date:3/23/2017)... The report "Gesture Recognition and Touchless Sensing Market by ... Global Forecast to 2022", published by MarketsandMarkets, the market is expected to be ... 2017 and 2022. Continue Reading ... ... ...
Breaking Biology News(10 mins):