Boffins work out how long DVDs will last

Scientists investigate properties of polymer glasses

Robert Jaques

Experts are a step closer to working out how long data stored on conventional media will last with the publication of a theory predicting how polymer glasses used in applications including DVDs decay over time.

Researchers at the University of Illinois explained that motions at the molecular level can have macroscopic consequences.

Advertisement

"Glasses, including polymer glasses, are essentially frozen liquids," said Kenneth S Schweizer, the G Ronald and Margaret H Morris Professor of Materials Science at the University of Illinois.

"They appear solid but, because they are frozen liquids, the molecules continually undergo small motions that lead to a time dependence of properties. "

Professor Schweizer and postdoctoral research associate Kang Chen presented the theory to describe the aging process in polymer glasses in the 20 April issue of Physical Review Letters.

The theory predicts not only how polymer molecules move, but the material's properties at a wide variety of times and temperatures.

The researchers explained that polymer glasses have melting points so close to room temperature that many retain some liquid-like properties at room temperature, including motion at the molecular level.

"The movements are so small and so slow that we cannot see them without the aid of sophisticated measuring tools," said Professor Schweizer.

"Nevertheless, this residual motion can significantly change the material's mechanical and thermal properties over time."

As the material gradually reconfigures and approaches equilibrium at room temperature, the movements become slower and slower.

Under sufficiently cold conditions, this "relaxation" time can become astronomically large, even longer than the age of the universe for some materials.

Over time, the molecules crowd closer together, increasing the density and changing the mechanical properties of the material.

"Through our theory we developed a way to relate the physical properties of a polymer glass to the timescale of molecular movement," explained Professor Schweizer.

"This information is especially important in engineering applications where small changes in dimensions, stiffness or other properties can affect long-term performance or reliability."

  • Have your say
  • Send to a friend
  • Print
  • Digg
  • Reddit
  • Share

Tags:

Do you agree?

Further reading

Related whitepapers

Related jobs

Most watched

eu flag

V3.co.uk weekly debrief, 6 Nov 09

This week, Europe decides what to do with illegal file sharers

Intel unveils its micro server platform

Small-enclosure systems take aim at hosting market

Analysis and Reports

Remote access - Three steps to getting connected

3.4 million UK professionals now work from home – is your company equipped?

Cost benefits of a global collaboration network

This white paper is a must read for organisations looking for evidence of the bottom-line benefits of high-definition video and voice communications

Poll

Impact of Information Overload poll

Impact of Information Overload poll

What is the biggest problem your firm faces as a result of the data explosion?

View poll results

Advertisement

White paper library

Keep up to date with the latest products, services and technologies from the world's leading IT companies; IThound.com brings you over 6,000 white papers, case studies and analyst reports.

Advertisement

Newsletter signup

Sign up for our range of FREE newsletters:

Existing User

Newsletter user login:

Enter email address to edit your newsletter preferences

Job of the week

Search thousands of IT jobs :

Search thousands of IT jobs:

Advanced search

Hiring now on ComputingCareers:

Related IT jobs

Search thousands of IT jobs :

Search thousands of IT jobs:

Advanced search

Advertisement

Spotlight

V3.co.uk Information Overload Summit starts today

We've finally cut the ribbon on V3.co.uk's inaugural Summit event...

rich media

Summit: Is the ECM industry up to the information overload challenge?

In part one of our report, we talk to EMC...

hacker

Summit: UK 'in danger of being left behind' on security

Experts warn behavioural monitoring is essential to protect sensitive data

Apple Magic Mouse

Review: Apple Magic Mouse

Multi-touch makes an appearance on Apple's latest mouse

Primary Navigation