Featured Research

from universities, journals, and other organizations

Rainbows without pigments offer new defense against fraud

Date:
May 19, 2011
Source:
University of Sheffield
Summary:
Scientists have developed pigment-free, intensely colored polymer materials, which could provide new, anti-counterfeit devices on passports or banknotes due to their difficulty to copy.

This multicolored image shows the range of colors that can be made by mixing the two block copolymers in varying proportions.
Credit: University of Sheffield

Scientists from the University of Sheffield have developed pigment-free, intensely coloured polymer materials, which could provide new, anti-counterfeit devices on passports or banknotes due to their difficulty to copy.

The polymers do not use pigments but instead exhibit intense colour due to their structure, similar to the way nature creates colour for beetle shells and butterfly wings.

These colours were created by highly ordered polymer layers, which the researchers produced using block copoylmers (an alloy of two different polymers). By mixing block copolymers together, the researchers were able to create any colour in the rainbow from two non-coloured solutions.

This type of polymer then automatically organises itself into a layered structure, causing optical effects similar to opals. The colour also changes depending on the viewing angle. This system has huge advantage in terms of cost, processing and colour selection compared to existing systems.

The complexity of the chemistry involved in making the polymer means they are very difficult for fraudsters to copy, making them ideally suited for use on passports or banknotes.

The academics used Diamond Light Source, the UK's national synchrotron science facility in Oxfordshire, to probe the ordered, layered structures using high power X-rays. This helped them understand how the colours were formed, and how to improve the appearance.

Dr Andrew Parnell, from the University of Sheffield's Department of Physics and Astronomy, said: "Our aim was to mimic the wonderful and funky coloured patterns found in nature, such as Peacock feathers. We now have a painter's palette of colours that we can choose from using just two polymers to do this. We think that these materials have huge potential to be used commercially."

Professor Nick Terrill, Principal Beamline Scientist for I22, the Diamond laboratory used for the experiment, explained: "Small Angle X-ray Scattering is a simple technique that in this case has provided valuable confirmatory information. By using Diamond's X-rays to confirm the structure of the polymer, the group was able to identify the appropriate blends for the colours required, meaning they can now tailor the polymer composition accordingly."

The institutions involved in the research include the University of Sheffield, the University of Hull and Diamond Light Source in Oxfordshire.


Story Source:

The above story is based on materials provided by University of Sheffield. Note: Materials may be edited for content and length.


Journal Reference:

  1. Andrew J. Parnell, Andrew Pryke, Oleksandr O. Mykhaylyk, Jonathan R. Howse, Ali. M. Adawi, Nicholas J. Terrill, J. Patrick A. Fairclough. Continuously tuneable optical filters from self-assembled block copolymer blends. Soft Matter, 2011; 7 (8): 3721 DOI: 10.1039/C0SM01320J

Cite This Page:

University of Sheffield. "Rainbows without pigments offer new defense against fraud." ScienceDaily. ScienceDaily, 19 May 2011. <www.sciencedaily.com/releases/2011/05/110518105724.htm>.
University of Sheffield. (2011, May 19). Rainbows without pigments offer new defense against fraud. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2011/05/110518105724.htm
University of Sheffield. "Rainbows without pigments offer new defense against fraud." ScienceDaily. www.sciencedaily.com/releases/2011/05/110518105724.htm (accessed September 19, 2014).

Share This



More Matter & Energy News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Virtual Reality Headsets Unveiled at Tokyo Game Show

Virtual Reality Headsets Unveiled at Tokyo Game Show

AFP (Sep. 18, 2014) Several companies unveiled virtual reality headsets at the Tokyo Game Show, Asia's largest digital entertainment exhibition. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Apple's iOS8 Includes New 'Killswitch' To Curb Theft

Apple's iOS8 Includes New 'Killswitch' To Curb Theft

Newsy (Sep. 18, 2014) Apple's new operating system, iOS 8, comes with Apple's killswitch feature already activated, unlike all the models before it. Video provided by Newsy
Powered by NewsLook.com
Stocks Hit All-Time High as Fed Holds Steady

Stocks Hit All-Time High as Fed Holds Steady

AP (Sep. 17, 2014) The Federal Reserve signaled Wednesday that it plans to keep a key interest rate at a record low because a broad range of U.S. economic measures remain subpar. Stocks hit an all-time high on the news. (Sept. 17) Video provided by AP
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins