Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Researchers show that carbon nanotubes are electrochromic

Carbon nanotube films change color when subject to an applied voltage. (© 2011 Wiley-VCH)
Carbon nanotube films change color when subject to an applied voltage. (© 2011 Wiley-VCH)

Abstract:
Smart glass can change color or even go from opaque to transparent with just the flick of a switch. Indium tin oxide is used as an electrical contact in many of these 'electrochromic' devices because it is both transparent to visible light and a good conductor of electricity. But indium and tin are both becoming increasingly expensive as the global supply diminishes.

Researchers show that carbon nanotubes are electrochromic

Tokyo, Japan | Posted on July 20th, 2011

Kazuhiro Yanagi from the Tokyo Metropolitan University, working with colleagues from across Japan, has now shown that carbon could be the perfect replacement.

Graphene sheets, consisting of a single atomic layer of carbon atoms in a honeycomb framework, can be rolled into a tube just a nanometer or so in diameter. These carbon nanotubes are highly conductive, mechanically strong, electrochemically stable and can show bright colors depending on how the sheet is rolled. Yanagi and his team have now shown that carbon nanotubes are also electrochromic.

The optical properties of carbon nanotubes can be altered by changing the density of electrons in the tube. Visible color change is achieved by applying a voltage of at least 2 V across tube when suspended in an electrolyte solution. Previous research has suggested that the nanotubes become photo-electrochemically unstable under these conditions. Yanagi and his colleagues, however, were able to prepare samples with good electrochemical stability using ionic liquids and density-gradient purifications. This combination reduced possible unexpected electrochemical reactions.

The novel electrochromic device consisted of a thin film of carbon nanotubes on a glass substrate. The team demonstrated the electrochromic function of their device using three different samples with different tube diameters. On application of a -3 V potential, 1.4 nm-diameter nanotubes went from a blue-green in color to yellow, 1.0 nm tubes turned from magenta to yellow-orange, and the initially yellow 0.84 nm sample changed to light yellow (see image). In all cases, the color returned to normal when the voltage was switched off. "Next, we would like to control the optical absorption causing the yellow color so we can get a highly transparent sheet of nanotubes, which could be important for electrochromic display applications," says Yanagi.

####

For more information, please click here

Contacts:
Committee for Public Relations
Tokyo Metropolitan University
1-1 Minami-Osawa, Hachioji-shi Tokyo, Japan 192-0397

Copyright © Tokyo Metropolitan University

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 Links

Electrochromic Carbon Electrodes: Controllable Visible Color Changes in Metallic Single-Wall Carbon Nanotubes

Related News Press

Graphene

Discovery Channel taps Angstron Materials for segment featuring graphene advances January 29th, 2015

Creating new materials with quantum effects for electronics January 29th, 2015

Graphenea sales more than double in 2014 January 29th, 2015

Researchers Make Magnetic Graphene: UC Riverside research could lead to new multi-functional electronic devices January 27th, 2015

Thin films

Los Alamos Develops New Technique for Growing High-Efficiency Perovskite Solar Cells: Researchers’ crystal-production insights resolve manufacturing difficulty January 29th, 2015

Detecting chemical weapons with a color-changing film January 28th, 2015

Electronic circuits with reconfigurable pathways closer to reality January 26th, 2015

Nanotubes/Buckyballs

Chromium-centered cycloparaphenylene rings for making functionalized nanocarbons January 26th, 2015

GS7 Graphene Sensor maybe Solution in Fight Against Cancer January 25th, 2015

Toyocolor to Launch New Carbon Nanotube Materials at nano tech 2015 January 24th, 2015

Carbon nanotube finding could lead to flexible electronics with longer battery life January 14th, 2015

Discoveries

Evidence mounts for quantum criticality theory: Findings bolster theory that quantum fluctuations drive strange electronic phenomena January 30th, 2015

Everything You Need To Know About Nanopesticides January 30th, 2015

DNA nanoswitches reveal how life's molecules connect: An accessible new way to study molecular interactions could lower cost and time associated with discovering new drugs January 30th, 2015

Crystal light: New light-converting materials point to cheaper, more efficient solar power: University of Toronto engineers study first single crystal perovskites for new solar cell and LED applications January 30th, 2015

Materials/Metamaterials

Evidence mounts for quantum criticality theory: Findings bolster theory that quantum fluctuations drive strange electronic phenomena January 30th, 2015

Crystal light: New light-converting materials point to cheaper, more efficient solar power: University of Toronto engineers study first single crystal perovskites for new solar cell and LED applications January 30th, 2015

The Original Frameless Shower Doors Installs DFI's FuseCube™ to Offer Hydrophobic Protective Coating as a Standard Feature: First DFI FuseCube™ Installed on the East Coast to Enable Key Differentiator for the Original Frameless Shower Doors January 29th, 2015

Creating new materials with quantum effects for electronics January 29th, 2015

Announcements

Evidence mounts for quantum criticality theory: Findings bolster theory that quantum fluctuations drive strange electronic phenomena January 30th, 2015

Everything You Need To Know About Nanopesticides January 30th, 2015

DNA nanoswitches reveal how life's molecules connect: An accessible new way to study molecular interactions could lower cost and time associated with discovering new drugs January 30th, 2015

Crystal light: New light-converting materials point to cheaper, more efficient solar power: University of Toronto engineers study first single crystal perovskites for new solar cell and LED applications January 30th, 2015

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 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE