Featured Research

from universities, journals, and other organizations

Two early stages of carbon nanotube growth discovered

Date:
October 3, 2011
Source:
Boston College
Summary:
Orderly rows of neatly aligned carbon nanotubes have served as the standard for nanotechnology researchers. But physicists now report the discovery of two early stages of carbon nanotube growth that produce tangled or semi-aligned tubes with characteristics that could lend themselves to thermal management and other applications.

Boston College researchers have discovered two early-stage phases of carbon nanotube growth during plasma enhanced chemical vapor deposition, finding a disorderly tangle of tube growth that ultimately yields to orderly rows of the nanoscopic tubes, according to a report in the latest edition of the journal Nanotechnology.

Related Articles


By using a thin layer of catalyst, Professor of Physics Zhifeng Ren and researcher Dr. Hengzhi Wang discovered two previously overlooked stages of carbon nanotube growth, they report. The method yields a first stage where budding tubes appear randomly entangled, then a second stage of partially aligned tubes, then a third and final stage of tubes in full alignment, which is the standard used by researchers who produce carbon nanotubes for use in a range of materials and biomedical research.

"These growth phases are controlled by the thickness of the catalyst in use," said Wang. "Each stage, it turns out, has its own merit. Each stage has its own purpose."

In plasma enhanced chemical vapor deposition, carbon nanotubes are grown through the repeated accumulation of carbon atoms from the decomposition of gasses upon a catalyst particle, which creates multilayered carbon material on a substrate. Researchers have sought to create neatly aligned rows of millions of carbon nanotubes upon the substrates.

"We didn't know why we were seeing these nanotube configurations," said Ren, among the pioneers in the development of aligned carbon nanotubes. "This is really why you are a scientist. You see a new phenomenon and then you try to understand it."

Ren and Wang say that in the process of achieving the third stage of nanotube growth, the two earlier phases of growth have gone overlooked as each stage is etched away by the next application of plasma. Further masking these early-stage carbon nanotubes is the fact that they are not present when a thick catalyst is used, according to their findings.

The first stage tubes, produced in zero to four minutes, are described as a tangle of random large and small diameter carbon nanotubes. The second stage tubes, created in four to ten minutes, are generally smaller in diameter, but taller and only partially aligned.

Wang says that while these nanotubes are not in neat, orderly rows, they do have the advantage of offer a larger volumetric density and create a larger surface area, which could be an important development in the use of carbon nanotubes in heat transfer in thermal management. A potential application could involve in applying a thin coating of carbon nanotubes to an integrated circuit in order to draw away heat and efficiently cool the device.

After ten minutes of plasma etching, the early stage nanotubes have been washed away and the third stage tubes begin to emerge in tall, ordered rows upon the substrate. At this stage, the tubes themselves are shielded by makeshift "helmets" of catalyst particles, which effectively protect them during the last part of the growth process. Eventually, these last bits of catalyst are etched away as well.


Story Source:

The above story is based on materials provided by Boston College. Note: Materials may be edited for content and length.


Cite This Page:

Boston College. "Two early stages of carbon nanotube growth discovered." ScienceDaily. ScienceDaily, 3 October 2011. <www.sciencedaily.com/releases/2011/10/111003080512.htm>.
Boston College. (2011, October 3). Two early stages of carbon nanotube growth discovered. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2011/10/111003080512.htm
Boston College. "Two early stages of carbon nanotube growth discovered." ScienceDaily. www.sciencedaily.com/releases/2011/10/111003080512.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NASA's First 3-D Printer In Space Creates Its First Object

NASA's First 3-D Printer In Space Creates Its First Object

Newsy (Nov. 26, 2014) The International Space Station is now using a proof-of-concept 3D printer to test additive printing in a weightless, isolated environment. Video provided by Newsy
Powered by NewsLook.com
Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Reuters - Innovations Video Online (Nov. 26, 2014) Innovative recycling project in La Paz separates city waste and converts plastic garbage into school furniture made from 'plastiwood'. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Blu-Ray Discs Getting Second Run As Solar Panels

Blu-Ray Discs Getting Second Run As Solar Panels

Newsy (Nov. 26, 2014) Researchers at Northwestern University are repurposing Blu-ray movies for better solar panel technology thanks to the discs' internal structures. Video provided by Newsy
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins