Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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/ Graphite

Researchers design one of the strongest, lightest materials known: Porous, 3-D forms of graphene developed at MIT can be 10 times as strong as steel but much lighter January 7th, 2017

Nano-chimneys can cool circuits: Rice University scientists calculate tweaks to graphene would form phonon-friendly cones January 4th, 2017

First use of graphene to detect cancer cells: System able to detect activity level of single interfaced cell December 20th, 2016

New graphene-based system could help us see electrical signaling in heart and nerve cells: Berkeley-Stanford team creates a system to visualize faint electric fields December 19th, 2016

Carbon dots dash toward 'green' recycling role: Rice scientists, colleagues use doped graphene quantum dots to reduce carbon dioxide to fuel December 18th, 2016

Thin films

New material with ferroelectricity and ferromagnetism may lead to better computer memory December 21st, 2016

Nanotubes/Buckyballs/Fullerenes

Captured on video: DNA nanotubes build a bridge between 2 molecular posts: Research may lead to new lines of direct communication with cells January 9th, 2017

Nano-chimneys can cool circuits: Rice University scientists calculate tweaks to graphene would form phonon-friendly cones January 4th, 2017

WPI researchers build liquid biopsy chip that detects metastatic cancer cells in blood December 15th, 2016

Infrared instrumentation leader secures exclusive use of Vantablack coating December 5th, 2016

Discoveries

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Nanoscale view of energy storage January 16th, 2017

Seeing the quantum future... literally: What if big data could help you see the future and prevent your mobile phone from breaking before it happened? January 16th, 2017

Materials/Metamaterials

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

NUS researchers achieve major breakthrough in flexible electronics: New classes of printable electrically conducting polymer materials make better electrodes for plastic electronics and advanced semiconductor devices January 14th, 2017

Manchester scientists tie the tightest knot ever achieved January 13th, 2017

Nanoscale Modifications can be used to Engineer Electrical Contacts for Nanodevices January 13th, 2017

Announcements

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Nanoscale view of energy storage January 16th, 2017

Seeing the quantum future... literally: What if big data could help you see the future and prevent your mobile phone from breaking before it happened? January 16th, 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