Magazine article Science News

Scattered Light Reveals Polymer Wave Motion

Magazine article Science News

Scattered Light Reveals Polymer Wave Motion

Article excerpt

Thin polymer films form the basis of products ranging from biological glues to nonstick coatings. In many applications, the polymer molecules stick out from a surface like grasses growing in a microscopic field. Rooted at one end, the molecules reach up and undulate as if blown by the wind.

A new method of characterizing these waves could lead to better understanding of the properties of polymer films. Researchers at the Institute of Electronic Structure and Laser in Heraklion, Greece, tracked the movements of tethered polymer molecules by measuring how they scatter light. The motions of the polymers can either enhance or interfere with the way they stick to surfaces, affecting their performance as paint primers and other coatings.

Although scientists have looked at the static properties of what they call polymer brushes-measuring their density, for example-this new technique is "definitely one of the first" ways to study their collective motion, says Anna C. Balazs of the University of Pittsburgh. "It's a very elegant technique. It's clever in that it isolates information that you're looking for, and it doesn't destroy the sample." The study appears in the Dec. 20 Science.

The team immersed one side of a glass prism in a solution containing suspended polymer molecules, which coated the surface. Each molecule consisted of a short segment of polyethyleneoxide, which stuck to the glass, and a longer chain of polystyrene, which stretched out into the solution.

The researchers then shone a laser beam through the prism so that it hit the interface between the glass and the solution at an angle shallow enough to reflect most of the beam. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.