ERIE, Pa. - The American Chemistry Council has awarded $100,000 to researchers at Penn State Behrend, where a team of polymer scientists is exploring the lower limits of microplastics and their potential impact in the environment, including Lake Erie.
The study may help scientists better isolate and identify various plastics that are found in the environment, the researchers said. That would help manufacturers better understand how polymers behave as they degrade - and how other materials might minimize the risk to plant and animal life.
"We're trying to take a step back and look at this from a different perspective," said Xiaoshi Zhang, an assistant professor of plastics engineering technology at Behrend and the lead researcher on the study. "We want to start by developing scientific approaches to understanding how plastics behave and how we can reliably detect them."
As they degrade, plastics often break into smaller pieces. The process isn't quick: It takes 50 years for a Styrofoam cup thrown into the ocean to fully degrade, according to the World Economic Forum. A strand of fishing line will retain some of its properties for up to 600 years.
"It can be difficult to detect those plastics as they degrade," Zhang said. "First of all, they're small. They also get mixed in with organic matter, minerals and glass. ... Some people are very eager to jump to the conclusion that it's plastic. The truth is, we don't always know. We don't have the right tests and processes in place."
Researchers typically use filters and static-charge screens to remove larger particles from a sample of material. They add hydrogen peroxide to dissolve any organic matter. Then, they heat a needle and touch it to the solid that remains. A microplastic will melt; glass won't.
"It's a very tedious process," Zhang said.
Using spectroscopy, researchers can study microplastics as small as 20 microns - roughly one-third the width of a human hair.
In a materials lab at Behrend, Zhang is testing a different method. Using an environmental scanning electron microscope and atomic-force microscopy, he can magnify the surface of a physical sample by up to one million times, seeing details as small as one nanometer.
That's beyond small: A page of notebook paper is about 100,000 nanometers thick.
"The hard part is being able to identify it as one plastic and not another," Zhang said. "That's the expertise we can bring to this. We know the properties of plastics pretty well."
Alicyn Rhoades, vice chancellor and associate dean for research and graduate studies, is assisting with the grant. Two researchers at the Energy and Environmental Sustainability Laboratories at University Park also are providing input: Hlengilizwe Nyoni, an assistant research professor, is using pyrolysis-gas chromatography and mass spectrometry to identify nanoplastics and determine their concentration. Maxwell Wetherington, an assistant research professor of molecular spectroscopy, is using AFM-IR, a technology for spectroscopic characterization, to identify the chemical structure of nanoplastics.
"We pulled together a team that can look at this problem in the right way," Rhoades said. "We have the right tools and the right people, and we understand both the reality of the industry and the importance of the lake environment. We are uniquely positioned to advance this."
The study also aligns with Behrend's Project RESOLVE, a regional strategy for shifting the plastics, metal-casting and transportation industries to a circular economic model that addresses plastic pollution in and near Lake Erie. A planned Center for Manufacturing Competitiveness will provide new labs and resources for Behrend researchers who study polymer science.
For Zhang, that begins with the development of a standard process for measuring and identifying microplastics in the environment. That could lead to changes in the polymers that manufacturers use, he said, and to the development of new materials, including biodegradable plastics.
"We aren't picking a side in the discussion of, 'Are plastics bad for the environment?'" he said. "We are trying to develop a standard for measuring these materials. That will allow us to better understand what's out there, and why it matters."
