Nanotechnology Now

Our NanoNews Digest Sponsors







Heifer International

Wikipedia Affiliate Button


Home > Press > Under pressure at the nanoscale, polymers play by different rules

Photo by L. Brian Stauffer
William P. King, a Kritzer Faculty Scholar and professor of mechanical engineering at Illinois, has discovered that at very short length scales the polymer doesn’t play by the rules.
Photo by L. Brian Stauffer
William P. King, a Kritzer Faculty Scholar and professor of mechanical engineering at Illinois, has discovered that at very short length scales the polymer doesn’t play by the rules.

Abstract:
Scientists putting the squeeze on thin films of polystyrene have discovered that at very short length scales the polymer doesn't play by the rules.

From buttons to storage bins, the molding of polymers is big business. At the nanoscale, processes such as nanoimprint lithography squeeze polymers to form patterns during the manufacture of semiconductor devices, organic electronics and optics. Thin films of polymer are important in adhesives, coatings and lubricants.

Under pressure at the nanoscale, polymers play by different rules

CHAMPAIGN, IL | Posted on October 2nd, 2008

"Although applications for nanoscale polymer flow are being widely investigated, the underlying, fundamental polymer physics is not," said William P. King, a Kritzer Faculty Scholar and professor of mechanical engineering at the University of Illinois.

"Understanding the way a polymer flows during nanoscale molding or imprinting processes is essential for designing new, nanoscale manufacturing processes," said King, who also is a researcher at the university's Beckman Institute.

In a paper to be published Thursday (Oct. 2), by Science Express, the online version of the journal Science, King and collaborators at the U. of I. and Trinity College, Dublin, report polymer squeeze flow measurements made at unprecedented, short length scales.

"We found an unexpected increase in the squeeze flow of thin films when the film thickness was smaller than 100 nanometers," King said. "This seemed backwards. Normally, you would expect the polymer to become harder and harder to press into thinner films."

The effect was even more pronounced in polymers of higher molecular weight, King said. "We expected the viscosity to increase with increasing molecular weight, but we found the opposite to be true when the films were thin enough."

Film thickness and molecular entanglement was the key, King said. In thick films, polymer chains are tangled together like cooked spaghetti. However, when the polymer film starts with a smaller initial thickness, a point is reached where the polymer chains change the way they interact with their neighbors. In very thin films, the polymer chains can no longer intertwine, and become like isolated blobs. This change in entanglement decreases the viscosity and increases the lateral squeeze flow.

To make the measurements, the researchers used a modified nanoscale indentation technique, which pressed a flat "punch" into very thin films of polystyrene. The punch, which was much wider than the thickness of the film, forced the polymer to flow around it. This lateral squeeze flow governs the dynamics of polymer movement during processes such as nanoimprint nanomanufacturing.

The research is a significant step forward in the understanding of polymer deformation that is directly related to nanoscale manufacturing, King said. "Our results suggest that polymer flow during nanoscale manufacturing may be enhanced by selecting polymers of higher molecular weight."

With King, co-authors of the paper are former U. of I. postdoctoral researcher Harry Rowland, and physics professor John Pethica and physics lecturer Graham Cross, both at Trinity College.

The work was funded by the Science Foundation of Ireland, the U.S. Department of Energy, and the U.S. National Science Foundation through the U. of I.'s Center for Nanoscale Chemical-Electrical-Mechanical Manufacturing Systems.

####

For more information, please click here

Contacts:
James E. Kloeppel
Physical Sciences Editor
217-244-1073


William King
217-244-3864


Copyright © University of Illinois at Urbana-Champaign

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

News and information

Nano-needles for cells May 25th, 2013

How do cold ions slide May 24th, 2013

Gold nanocrystal vibration captured on billion-frames-per-second film May 23rd, 2013

Glowing Plant Releases Maker Kit, Enabling Anyone to Make a Glowing Plant at Home: Glowing Plant seeks funds via crowdfunding and raises almost $400,000 May 23rd, 2013

Thin films

IDTechEx launches online Market Intelligence Portal May 23rd, 2013

Weird science: Crystals melt when they're cooled May 22nd, 2013

Moth-Inspired Nanostructures Take the Color Out of Thin Films May 17th, 2013

New magnetic graphene may revolutionise electronics May 11th, 2013

Govt.-Legislation/Regulation/Funding/Policy

How do cold ions slide May 24th, 2013

Gold nanocrystal vibration captured on billion-frames-per-second film May 23rd, 2013

Whirlpools on the Nanoscale Could Multiply Magnetic Memory: At the Advanced Light Source, Berkeley Lab scientists join an international team to control spin orientation in magnetic nanodisks May 22nd, 2013

Atomic-Scale Investigations Solve Key Puzzle of LED Efficiency: MIT and Brookhaven Lab scientists use electron microscopy imaging techniques to settle a solid-state controversy and raise new experimental possibilities May 22nd, 2013

Discoveries

Nano-needles for cells May 25th, 2013

How do cold ions slide May 24th, 2013

Gold nanocrystal vibration captured on billion-frames-per-second film May 23rd, 2013

Atomic-Scale Investigations Solve Key Puzzle of LED Efficiency: MIT and Brookhaven Lab scientists use electron microscopy imaging techniques to settle a solid-state controversy and raise new experimental possibilities May 22nd, 2013

Materials

Gold nanocrystal vibration captured on billion-frames-per-second film May 23rd, 2013

IDTechEx launches online Market Intelligence Portal May 23rd, 2013

Weird science: Crystals melt when they're cooled May 22nd, 2013

INSCX™ exchange announces substantial increase in capital designated to provide Trade Finance for registered Nanomaterial Producers May 21st, 2013

Announcements

Nano-needles for cells May 25th, 2013

How do cold ions slide May 24th, 2013

Gold nanocrystal vibration captured on billion-frames-per-second film May 23rd, 2013

Glowing Plant Releases Maker Kit, Enabling Anyone to Make a Glowing Plant at Home: Glowing Plant seeks funds via crowdfunding and raises almost $400,000 May 23rd, 2013

Printing/Lithography/Inkjet

IDTechEx launches online Market Intelligence Portal May 23rd, 2013

Rice unveils method for tailoring optical processors: Arranging nanoparticles in geometric patterns allows for control of light with light May 21st, 2013

NanoInk, Inc. Assets To Be Sold May 18th, 2013

Glowing Plant Kickstarter Project Retains Digital Marketing Agency, Command Partners: Glowing Plant brings on top Charlotte-based digital marketing firm to assist in crowdfunding campaign May 16th, 2013

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








abbigliamento uomo
Computer Accessories
© Copyright 1999-2013 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE