Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

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

Fast, stretchy circuits could yield new wave of wearable electronics May 30th, 2016

Automating DNA origami opens door to many new uses: Like 3-D printing did for larger objects, method makes it easy to build nanoparticles out of DNA May 30th, 2016

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Imaging

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Light can 'heal' defects in new solar cell materials: Defects in some new electronic materials can be removed by making ions move under illumination May 24th, 2016

More light on cancer: Scientists created nanoparticles to highlight cancer cells May 21st, 2016

Nanotubes/Buckyballs/Fullerenes

Programmable materials find strength in molecular repetition May 23rd, 2016

Nanotubes are beacons in cancer-imaging technique: Rice University researchers use spectral triangulation to pinpoint location of tumors May 21st, 2016

Unveiling the electron's motion in a carbon nanocoil: Development of a precise resistivity measurement system for quasi-one-dimensional nanomaterials using a focused ion beam May 16th, 2016

New research shows how silver could be the key to gold-standard flexible gadgets: Silver nanowires are an ideal material for current and future flexible touch-screen technologies May 13th, 2016

Sensors

The next generation of carbon monoxide nanosensors May 26th, 2016

Dartmouth team creates new method to control quantum systems May 24th, 2016

Electronic device detects molecules linked to cancer, Alzheimer's and Parkinson's: An inexpensive portable biosensor has been developed by researchers at Brazil's National Nanotechnology Laboratory with FAPESP's support May 20th, 2016

Making organs transparent to improve nanomedicine (video) May 13th, 2016

Discoveries

Fast, stretchy circuits could yield new wave of wearable electronics May 30th, 2016

Automating DNA origami opens door to many new uses: Like 3-D printing did for larger objects, method makes it easy to build nanoparticles out of DNA May 30th, 2016

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Announcements

Fast, stretchy circuits could yield new wave of wearable electronics May 30th, 2016

Automating DNA origami opens door to many new uses: Like 3-D printing did for larger objects, method makes it easy to build nanoparticles out of DNA May 30th, 2016

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Energy

Harnessing solar and wind energy in one device could power the 'Internet of Things' May 26th, 2016

Gigantic ultrafast spin currents: Scientists from TU Wien (Vienna) are proposing a new method for creating extremely strong spin currents. They are essential for spintronics, a technology that could replace today's electronics May 25th, 2016

Light can 'heal' defects in new solar cell materials: Defects in some new electronic materials can be removed by making ions move under illumination May 24th, 2016

Technique improves the efficacy of fuel cells: Research demonstrates a new phase transition from metal to ionic conductor May 18th, 2016

Battery Technology/Capacitors/Generators/Piezoelectrics/Thermoelectrics/Energy storage

Distance wireless charging enhanced by magnetic metamaterials: A metamaterial shell is capable of multiplying transmission efficiency several times over May 13th, 2016

Abalonyx launches Reduced Graphene Oxide Product: Abalonyx has successfully scaled up production of thermally reduced graphene oxide (rGO) in its Tofte, Norway, production facility. This product is now offered to customers in Kg-quantities May 10th, 2016

Visualizing the Lithiation of a Nanosized Iron-Oxide Material in Real Time: Electron microscopy technique reveals the reaction pathways that emerge as lithium ions are added to magnetite nanoparticles May 9th, 2016

Speedy ion conduction in solid electrolytes clears road for advanced energy devices May 5th, 2016

Research partnerships

Finding a new formula for concrete: Researchers look to bones and shells as blueprints for stronger, more durable concrete May 26th, 2016

The next generation of carbon monoxide nanosensors May 26th, 2016

Revealing the nature of magnetic interactions in manganese oxide: New technique for probing local magnetic interactions confirms 'superexchange' model that explains how the material gets its long-range magnetic order May 25th, 2016

Light can 'heal' defects in new solar cell materials: Defects in some new electronic materials can be removed by making ions move under illumination May 24th, 2016

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







Car Brands
Buy website traffic