Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Temperature-sensitive Nanobrushes

Abstract:
Electrically conducting polymer with temperature-dependent optical properties and water solubility

Temperature-sensitive Nanobrushes

July 13, 2005

The terms plastic and electrical current usually bring to mind such things as insulators or computer cases. It goes without saying that plastics are insulators, right? The discovery of conducting polymers actually resulted in a Nobel Prize in Chemistry for A.J. Heeger, A.G. MacDiarmid and H. Shirakawa in 2000 - "plastic electronics" are on the move. An American team has now developed a conducting polythiophene that demonstrates amazingly high water solubility and responds to the surrounding temperature as well.

Why the interest in electrically conducting polymers that are water-soluble? Water solubility allows for more environmentally friendly production processes. In addition, it is a requirement for many biological and diagnostic applications. Certain conducting polymers also respond to changes in their environment by a color change. This is just the thing for sensors that detect specific analyte molecules or indicate other parameters.

Polythiophenes, the most economically important class of conducting polymers, consist of long chains of five-membered rings containing four carbon atoms and one sulfur atom. Researchers led by Robin L. McCarley at Louisiana State University attached chains of a polyacrylamide derivative to a polythiophene backbone like bristles on the handle of a bottle brush. The "bristles" make the molecular "brushes" the most water-soluble neutral polythiophenes found to date.

But these bristles can do more: they respond sensitively to temperature changes. At temperatures under 30 °C, the brushes are in an irregular, stretched-out form and are loaded with water molecules. If the temperature is raised above 32 °C, these structures collapse into compact spheres, pushing the water molecules out. As a result, the entire brush responds to the conformational change of its bristles. From a stretched-out, only slightly balled-up form, it pulls itself into a compact spherical structure. This change decreases the water solubility of the brushes. More significantly, at the same time, the color changes; whereas a solution of the brushes at low temperature is orange-red in appearance, higher temperatures cause the color to change to yellow. This change in color indicates shifts in the electrical properties of the backbone.

Such water-soluble polymeric brushes, which react to external stimulation by changing their opto-electronic properties, could be used for biosensors in bioelectronics, as nanoswitches, light-emitting diodes, or fluorescence thermometers.

Author: Robin L. McCarley, Louisiana State University, Baton Rouge (USA),

####

Contact:
Editorial office
angewandte@wiley-vch.de

David Greenberg (US)
dgreenbe@wiley.com

Julia Lampam (UK)
jlampam@wiley.co.uk

Copyright © Angewandte Chemie

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

Possible Futures

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

Nanotechnology in Energy Applications Market Research Report 2014-2018: Radiant Insights, Inc January 15th, 2015

'Mind the gap' between atomically thin materials December 23rd, 2014

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Sensors

Detection of Heavy Metals in Samples with Naked Eye January 26th, 2015

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

Nanosensor Used for Simultaneous Determination of Effective Tea Components January 24th, 2015

Iranian Scientists Produce Graphene-Based Oxygen Sensor January 23rd, 2015

Announcements

Nanoparticles Increase Durability of Concrete Decorations in Cold Areas January 26th, 2015

Iranian Researchers Boost Solar Cells Efficiency Using Anti-Aggregates January 26th, 2015

Detection of Heavy Metals in Samples with Naked Eye January 26th, 2015

Engineering self-assembling amyloid fibers January 26th, 2015

Environment

Detection of Heavy Metals in Samples with Naked Eye January 26th, 2015

Magnetic Nanosorbents Able to Eliminate Chemical Contaminants January 19th, 2015

Malaysian Nanotechnology Company Nanopac Innovation Ltd. lists on the NSX January 19th, 2015

Iran Designs Magnetic Nano-Absorbents Cleaning Chemical Pollutants January 11th, 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