In the August 9-13 edition of the Proceedings of the National Academy of Sciences, the team presents a new way to image and analyze the mechanical stress that causes colloidal coatings—those in which microscopic particles of one substance are dispersed throughout another—to peel off of surfaces.
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.”
To visualize the microscopic motion of paint in 3D, the team mixed in tiny fluorescent particles that glow when illuminated by a laser. By tracing the motion of these particles over time with a microscope, they captured the motion of the paint as it peeled and dried in detail.
In addition, the team was able to track the 3-D forces generated by the paint as it dried, producing a “stress map” of the mechanical deformation of the coating as it failed. “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.
Although the current study focuses on colloidal coatings, the technique could be applied to all kinds of coatings, 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.”
Other authors of the study include Ye Xu, Wilfried Engl, Elizabeth Jerison and Callen Hyland (Yale University); Kevin Wallenstein (Princeton University); and Larry Wilen (Unilever).
Citation: DOI: 10.1073/pnas.1005537107
PRESS CONTACT: Suzanne Taylor Muzzin 203-432-8555
Suzanne Taylor Muzzin | EurekAlert!
Amputees can learn to control a robotic arm with their minds
28.11.2017 | University of Chicago Medical Center
The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
12.12.2017 | Physics and Astronomy
12.12.2017 | Earth Sciences
12.12.2017 | Power and Electrical Engineering