Study: Coatings Release Nanoparticles
Integrating nanoparticles into coatings is one of the most rapidly developing fields in coatings technology right now, but researchers from the National Institute of Standards and Technology have been looking not at the short-term gains from nanoparticle-dispersed coatings, but rather at some of the possible long-term consequences.
Scientists at the U.S. government-run center recently published a paper looking at findings from accelerated weathering testing they did on a particular commercially available nanoparticle-infused coating, and their findings point to the idea that long-term exposure could lead to the release of nanoparticles from the coating into the environment.
The ultimate effects of various nanoparticles making their way into the environment aren't really understood yet; this preliminary research is cause for more investigation, the NIST says.
Humidity, UV Exposure Factors
The coating the scientists tested was a nanosilica/polyurethane coating; their study, published in the Journal of Coatings Technology and Research, builds on other NIST research related to epoxy nanocomposites. Nanosilica-dispersed polyurethanes have been developed for qualities including hydrophobicity and scratch resistance.
The most notable finding of the new NIST study, according to the researchers, is that exposure to high humidity coupled with a long period of UV exposure led to more significant releases of silica nanoparticles from the coating. Samples weathered in low humidity released some nanoparticles, but not as many.
The nanoparticles, when they were released from the coating material, “often bound together in clusters,” according to NIST.
Affect on Industry
The discoveries from this and other studies related to nanoparticle-dispersed coatings could affect how manufacturers approach the developing field, and how governments and industry groups choose to regulate the coatings.
“These data, and the data from future experiments of this type, are valuable for developing computer models to predict the long-term release of nanoparticles from commercial coatings used outdoors, and in turn, help manufacturers, regulatory officials and others assess any health and environmental impacts from them,” said NIST research chemist Deborah Jacobs, lead author on the study.
Other authors on the study are: Sin-Ru Huang, Yu-Lun Cheng, Savelas A. Rabb, Justin M. Gorham, Peter J. Krommenhoek, Lee L. Yu, Tinh Nguyen and Lipiin Sung.
The research was a collaboration between the NIST’s Engineering Laboratory and Material Measurement Laboratory. The NIST, which received $971.3 million in federal funding in 2016, is dedicated to promoting U.S. innovation and industrial competitiveness by advancing measurement science, standards and technology in ways that enhance economic security and improve Americans’ quality of life.