How are nanomaterials affecting the environment—and us? With a new grant renewal, CEINT researchers seek answers
By Karyn Hede
The nanomaterials revolution has made exceedingly tiny engineered particles a hot commodity, used in products from clothing to sunscreen to electronics. But the very properties that make them so useful -- vanishingly small size and high surface area—may have unintended consequences as they enter living organisms and the environment.
A pioneering, multi-institution research center headquartered at Duke's Pratt School of Engineering has just won $15-million grant renewal from the National Science Foundation and the US Environmental Protection Agency to continue learning more about where nanoparticles accumulate, how they interact with other chemicals and how they affect the environment.
Duke researchers developed a hyperspectral imaging technique to help them visualize and survey nanoparticles in water samples. Shown here are specially coated silver nanoparticles floating in mesocosm water (scale - 1 centimeter=250 microns, or 250 millionths of a meter). The average diameter of the nanoparticles is 55 nanometers, or 55 billionths of a meter, but variations in size cause them to reflect different colors as shown in the image. Credit - Appala Raju Badireddy
“The previous focus has been on studying simple, uniform nanomaterials in simple environments, ” said Mark Wiesner, James L. Meriam Professor of Civil & Environmental Engineering and director of CEINT. “As we look to the next five years, we envision a dramatically different landscape. We will be evaluating more complex nanomaterials in more realistic natural environments such as agricultural lands and water treatment systems where these materials are likely to be found.”
When CEINT formed, little research had been done on how materials manufactured at the nanoscale—about 1/10, 000th the diameter of a human hair—enter the environment and whether their size and unique properties render them a new category of environmental risk. For example, nanoparticles can be highly reactive with other chemicals in the environment and had been shown to disrupt activities in living organisms. Indeed, nanosilver is used in clothing precisely because it effectively kills odor-causing bacteria.
