Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Boston College Researchers Discover Two Early Stages Of Carbon Nanotube Growth

Abstract:
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.

Boston College Researchers Discover Two Early Stages Of Carbon Nanotube Growth

Chestnut Hill, MA | Posted on October 3rd, 2011

By using a thin layer of catalyst, Professor of Physics Zhifeng Ren and researcher 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.

--Ed Hayward

####

For more information, please click here

Contacts:
Ed Hayward
Boston College News & Public Affairs

Copyright © Boston College

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Leti to Demo Wristband with Embedded Sensors to Diagnose Sleep Apnea: APNEAband, Which Will Be Demonstrated at CES 2018, Also Monitors Mountain Sickness, Dehydration, Dialysis Treatment Response and Epileptic Seizures December 12th, 2017

Leti Develops World’s First Micro-Coolers for CERN Particle Detectors: Leti Design, Fabrication and Packaging Expertise Extends to Very Large Scientific Instruments December 11th, 2017

Untangling DNA: Researchers filter the entropy out of nanopore measurements December 8th, 2017

Device makes power conversion more efficient: New design could dramatically cut energy waste in electric vehicles, data centers, and the power grid December 8th, 2017

Nanotubes/Buckyballs/Fullerenes/Nanorods

Scientists make transparent materials absorb light December 1st, 2017

Researchers advance technique to detect ovarian cancer: Rice, MD Anderson use fluorescent carbon nanotube probes to achieve first in vivo success November 30th, 2017

NanoSummit in Luxembourg: single wall carbon nanotubes have entered our lives as we approach a nanoaugmented future November 23rd, 2017

Fine felted nanotubes : Research team of Kiel University develops new composite material made of carbon nanotubes November 22nd, 2017

Discoveries

UCLA chemists synthesize narrow ribbons of graphene using only light and heat: Tiny structures could be next-generation solution for smaller electronic devices December 8th, 2017

Untangling DNA: Researchers filter the entropy out of nanopore measurements December 8th, 2017

Device makes power conversion more efficient: New design could dramatically cut energy waste in electric vehicles, data centers, and the power grid December 8th, 2017

Wheat gets boost from purified nanotubes: Rice University toxicity study shows plant growth enhanced by -- but only by -- purified nanotubes December 6th, 2017

Announcements

Leti to Demo Wristband with Embedded Sensors to Diagnose Sleep Apnea: APNEAband, Which Will Be Demonstrated at CES 2018, Also Monitors Mountain Sickness, Dehydration, Dialysis Treatment Response and Epileptic Seizures December 12th, 2017

Leti Develops World’s First Micro-Coolers for CERN Particle Detectors: Leti Design, Fabrication and Packaging Expertise Extends to Very Large Scientific Instruments December 11th, 2017

Untangling DNA: Researchers filter the entropy out of nanopore measurements December 8th, 2017

Device makes power conversion more efficient: New design could dramatically cut energy waste in electric vehicles, data centers, and the power grid December 8th, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project