Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Controlling chemistry improves potential of carbon nanotubes

Left: The Billups-Birch alkylcarboxylation reaction allows functional groups to propagate down the CNT from points of pre-existing defects. Right: Electron microscopy shows “banded” CNTs with distinct functionalized and intact regions along their lengths. Photo credits: Nature Communications.
Left: The Billups-Birch alkylcarboxylation reaction allows functional groups to propagate down the CNT from points of pre-existing defects. Right: Electron microscopy shows “banded” CNTs with distinct functionalized and intact regions along their lengths. Photo credits: Nature Communications.

Abstract:
A team of University of Maryland nanotechnology researchers has solved one of the most vexing challenges hindering the use of carbon nanomaterials in increasing electrical energy storage efficiency in batteries or enhancing the fluorescence sensing capabilities of biosensors. The findings are published in the July 12 issue of Nature Communications.

Controlling chemistry improves potential of carbon nanotubes

College Park, MD | Posted on July 12th, 2011

The breakthrough research was led by Chemistry Assistant Professor YuHuang Wang and conducted in the Nanostructures for Electrical Energy Storage center (an Energy Frontier Research Center of the Department of Energy), Northwestern University, and the Maryland NanoCenter.

Carbon nanotubes (CNTs) have enormous potential. They are some of the most conductive structures ever made—highly efficient electrodes with enormous surface area. To take full advantage of these properties, however, CNTs must be soluble—that is, have the ability to be dispersed in a liquid environment or to evenly coat a solid composite material. Unfortunately, in their raw state CNTs are insoluble; they clump together rather than disperse.

For more than a decade, researchers have been developing new chemical processes to address this challenge. One idea has been to create permanent defects on the surfaces of CNTs and "functionalize" them so they are soluble. Unfortunately, this also has the undesired side effect of quickly destroying the CNTs' electrical and optical properties.

Wang and his team have developed a new functionalization process for CNTs that delivers solubility and preserves electrical and optical properties. They purposefully functionalize defects on the tubes in useful—not random—places, creating strategic "functional groups." These carefully placed molecular groups allow CNTs to readily disperse while retaining their optical properties and ability to conduct electric current in large regions along the tube.

The challenge has been to control the chemical reactions that produce the functional groups on the CNTs. By using a chemical process called Billups-Birch reductive alkylcarboxylation, Wang's team found they could progressively add new functional groups to the CNT wall in a controlled way without introducing unintended new defects.

When the CNTs are immersed in a chemical solution for a specific length of time, the functionalized groups on the nanotubes lengthen by a predictable amount. Each time the process is repeated, or as the time in the solution increases, the sections grow longer. When the CNTs are viewed under a special, high magnification electron microscope, it is evident that the functionalization has progressed lengthwise along the tube.

The propagation can initiate from either naturally occurring or intentionally introduced defects. Because the propagation mechanism confines the reaction and strategically controls where the functional groups grow, Wang's team can produce clustered functional groups at a controlled, constant propagation rate. It is the first clearly established wet chemistry process that does so.

The breakthrough makes it possible to create new functional structures such as "banded" nanotubes with alternating segments of functionalized and intact regions. The functionalized regions keep the CNTs from clumping, making them among the most water-soluble CNTs known. At the same time, the bands of intact, non-functionalized regions of the CNTs allow electrical and optical properties to be retained.

"This is important for the future use of these materials in batteries and solar cells where efficient charge collection and transport are sought," Wang explains. "These CNTs also could be used as highly sensitive biochemical sensors because of their sharp optical absorption and long-lived fluorescence in the near infrared regions where tissues are nearly optically transparent."

"This is a major step towards building the controlled nanostructures needed to understand electrochemical science and its value for energy solutions," says University of Maryland NanoCenter Director, Professor Gary Rubloff (MSE/ISR), a collaborator on the project.

The research team also includes theoretical chemist Professor George Schatz of Northwestern University, postdoctoral associates and graduate students Shunliu Deng, Yin Zhang, and Alexandra Brozena, who are equal contribution first authors, as well as Maricris Mayes, Parag Banerjee and Maryland NanoCenter staff member Wen-An Chiou.

####

For more information, please click here

Contacts:
Maryland NanoCenter
Kim Engineering Building
University of Maryland
College Park, MD 20742

Request Info

Copyright © University of Maryland

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

Seeking Nanoscale Defenses for Biological and Chemical Threats: WPI co-organizes a NATO workshop to improve the detection and decontamination of biological and chemical agents September 13th, 2014

New pricing report for bulk graphene materials September 13th, 2014

Berkeley Lab Licenses Boron Nitride Nanotube Technology: New material has unique mechanical and electronic properties September 13th, 2014

Iranian Nano Scientists Create Flame-Resistant Polymers September 13th, 2014

Imaging

Advanced Light Source Sets Microscopy Record| Berkeley Lab Researchers Achieve Highest Resolution Ever with X-ray Microscopy September 11th, 2014

Researchers Create World’s Largest DNA Origami September 11th, 2014

Development of Algorithm for Accurate Calculation of Average Distance Travelled by Low-Speed Electrons without Energy Loss that Are Sensitive to Surface Structure September 11th, 2014

How skin falls apart: The pathology of autoimmune skin disease is revealed at the nanoscale September 10th, 2014

Nanotubes/Buckyballs

Berkeley Lab Licenses Boron Nitride Nanotube Technology: New material has unique mechanical and electronic properties September 13th, 2014

Global Energy Systems Signs Master Sales Agreement with China Aviation Supplies Group September 4th, 2014

Breakthrough for Carbon Nanotube Solar Cells: Polychiral carbon nanotube mixture absorbs more sunlight September 3rd, 2014

SouthWest NanoTechnologies CEO Dave Arthur to Discuss “Carbon Nanotubes and Automotive Applications” at The Automotive Composites Conference and Expo 2014 (ACCE2014) August 28th, 2014

Sensors

First Colloid and Polymer Science Lecture awarded to Orlin D. Velev: Chemical engineer honored for outstanding research in colloid science September 12th, 2014

UT Arlington research uses nanotechnology to help cool electrons with no external sources September 11th, 2014

Development of Algorithm for Accurate Calculation of Average Distance Travelled by Low-Speed Electrons without Energy Loss that Are Sensitive to Surface Structure September 11th, 2014

Layered graphene sandwich for next generation electronics September 8th, 2014

Discoveries

Iranian Nano Scientists Create Flame-Resistant Polymers September 13th, 2014

Boosting armor for nuclear-waste eating microbes September 12th, 2014

Ceramics don't have to be brittle: Caltech materials scientists are creating materials by design September 11th, 2014

Researchers Create World’s Largest DNA Origami September 11th, 2014

Announcements

Seeking Nanoscale Defenses for Biological and Chemical Threats: WPI co-organizes a NATO workshop to improve the detection and decontamination of biological and chemical agents September 13th, 2014

New pricing report for bulk graphene materials September 13th, 2014

Berkeley Lab Licenses Boron Nitride Nanotube Technology: New material has unique mechanical and electronic properties September 13th, 2014

Iranian Nano Scientists Create Flame-Resistant Polymers September 13th, 2014

Energy

UT Arlington research uses nanotechnology to help cool electrons with no external sources September 11th, 2014

Excitonic Dark States Shed Light on TMDC Atomic Layers: Berkeley Lab Discovery Holds Promise for Nanoelectronic and Photonic Applications September 11th, 2014

Indium/Copper Sulfide Compound Semi-Conductor Synthesized through New Method September 8th, 2014

Breakthrough for Carbon Nanotube Solar Cells: Polychiral carbon nanotube mixture absorbs more sunlight September 3rd, 2014

Battery Technology/Capacitors/Generators/Piezoelectrics/Thermoelectrics

NEI Corporation and PneumatiCoat Technologies Sign Agreement to Jointly Develop and Market New Materials for Lithium-ion Batteries September 12th, 2014

UT Arlington research uses nanotechnology to help cool electrons with no external sources September 11th, 2014

Development of Algorithm for Accurate Calculation of Average Distance Travelled by Low-Speed Electrons without Energy Loss that Are Sensitive to Surface Structure September 11th, 2014

New analytical technology reveals 'nanomechanical' surface traits August 29th, 2014

Research partnerships

NEI Corporation and PneumatiCoat Technologies Sign Agreement to Jointly Develop and Market New Materials for Lithium-ion Batteries September 12th, 2014

Advanced Light Source Sets Microscopy Record| Berkeley Lab Researchers Achieve Highest Resolution Ever with X-ray Microscopy September 11th, 2014

Researchers Create World’s Largest DNA Origami September 11th, 2014

Development of Algorithm for Accurate Calculation of Average Distance Travelled by Low-Speed Electrons without Energy Loss that Are Sensitive to Surface Structure September 11th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE