How paint dries and peels off

WASHINGTON - Yale University researchers have come up with a new technique that let’s them take a close look at the mechanics of coating as they dry and peel off.

Understanding how and why coatings fail has broad applications in the physical and biological sciences, said Eric Dufresne, the John J. Lee Associate Professor of Mechanical Engineering at Yale and lead author of the study.

“Coatings protect almost every surface you encounter, from paint on a wall to Teflon on a frying pan to the skin on our own bodies. When coatings peel and crack they put the underlying material at risk,” Dufresne said.

“Our research is aimed at pinpointing the failure of coatings. We’ve developed this new technique to zoom in on coatings and watch them fail at the microscopic level,” he added.

The team mixed in tiny fluorescent particles that glow when illuminated by a laser, in order to get all the action in 3D. They then coated the paint on a rubber surface.

“The trick was to apply the paint to a soft surface, made of silicone rubber, that is ever so slightly deformed by the gentle forces exerted by the drying paint,” Dufresne said.

Next, the team hopes to improve on current methods for mitigating peeling in a wide range of coatings.

“This is a completely new way of looking at a very old problem,” he said.

The study is published in the August 9-13 edition of the Proceedings of the National Academy of Sciences. (ANI)