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

Imaging

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

News and information

NanoTechnology for Defense (NT4D) October 22nd, 2014

Mechanism behind nature's sparkles revealed October 22nd, 2014

TARA Biosystems and Harris & Harris Group Form Company to Improve Safety and Efficacy of New Therapies October 22nd, 2014

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Nanotubes/Buckyballs

Materials for the next generation of electronics and photovoltaics: MacArthur Fellow develops new uses for carbon nanotubes October 21st, 2014

Special UO microscope captures defects in nanotubes: University of Oregon chemists provide a detailed view of traps that disrupt energy flow, possibly pointing toward improved charge-carrying devices October 21st, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Beyond LEDs: Brighter, new energy-saving flat panel lights based on carbon nanotubes - Planar light source using a phosphor screen with highly crystalline single-walled carbon nanotubes (SWCNTs) as field emitters demonstrates its potential for energy-efficient lighting device October 14th, 2014

Sensors

Journal Nanotechnology Progress International (JONPI), 2014, Volume 5, Issue 1, pp 1-24 October 22nd, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Graphenea opens US branch October 16th, 2014

IRLYNX and CEA-Leti to Streamline New CMOS-based Infrared Sensing Modules Dedicated to Human-activities Characterization October 15th, 2014

Discoveries

Bipolar Disorder Discovery at the Nano Level: Tiny structures found in brain synapses help scientists better understand disorder October 22nd, 2014

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Mechanism behind nature's sparkles revealed October 22nd, 2014

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Announcements

NanoTechnology for Defense (NT4D) October 22nd, 2014

Mechanism behind nature's sparkles revealed October 22nd, 2014

TARA Biosystems and Harris & Harris Group Form Company to Improve Safety and Efficacy of New Therapies October 22nd, 2014

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Energy

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Could I squeeze by you? Ames Laboratory scientists model molecular movement within narrow channels of mesoporous nanoparticles October 21st, 2014

First Canada Excellence Research Chair gets $10 million from the federal government for oilsands research at the University of Calgary: Federal government announces prestigious research chair to study improving oil production efficiency October 19th, 2014

Magnetic mirrors enable new technologies by reflecting light in uncanny ways October 16th, 2014

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

Super stable garnet ceramics may be ideal for high-energy lithium batteries October 21st, 2014

Graphenea opens US branch October 16th, 2014

NTU develops ultra-fast charging batteries that last 20 years October 14th, 2014

Electrically conductive plastics promising for batteries, solar cells October 10th, 2014

Research partnerships

Brookhaven Lab Launches Computational Science Initiative:Leveraging computational science expertise and investments across the Laboratory to tackle "big data" challenges October 22nd, 2014

Detecting Cancer Earlier is Goal of Rutgers-Developed Medical Imaging Technology: Rare earth nanocrystals and infrared light can reveal small cancerous tumors and cardiovascular lesions October 21st, 2014

Nitrogen Doped Graphene Characterized by Iranian, Russian, German Scientists October 21st, 2014

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 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