Model Systems to Study Mechanisms for Mass Transfer from Nanotechnology-Enabled Polymers into Foods and the Environment

Polymer nanocomposites (PNCs) are materials in which nanoscale fillers are dispersed within a polymer host matrix. Despite excitement surrounding potential applications, there is a need for additional information on whether the embedded nanofillers may become released into the nearby environment during product lifecycles. Our group adopts a bottom-up experimental strategy to study potential exposure pathways that relies on well-characterized model systems, which are designed to investigate specific relationships between nanofiller characteristics and release kinetics. In this talk, we present several model systems developed in our laboratory based on semiconducting quantum dots or other nanofillers. We incorporated well-characterized nanofillers into appropriately chosen polymers by melt compounding and immersed the resulting model PNCs in liquid media intended to simulate the properties of certain foods or environmental media. Using chemical and materials analysis techniques, our model systems provide a different view of the effect of the external medium chemistry, environmental conditions, and particle size/composition on release phenomena, as well as draw fundamental conclusions about primary release mechanisms. This work shows that model systems offer a powerful experimental compliment to the use of commercial PNCs when it comes to lifecycle analysis of nanotechnology-enabled materials.

About the speaker

Timothy V. Duncan received his undergraduate degree in chemistry in 2000 from Haverford College, located just outside of Philadelphia. He attained his Ph.D. in physical/inorganic chemistry in 2006 from the University of Pennsylvania, where he synthesized and studied the photophysical properties of conjugated porphyrin arrays designed for medical diagnostic and optoelectronic applications under Professor Michael J. Therien. After graduation, he did a postdoc at the University of Pennsylvania in the lab of Professor So-Jung Park, where he built a single-molecule fluorescence imaging system in order to study the light emission properties of novel quantum-dot based bio-imaging agents and devised a new method to synthesize color-tunable conducting polymers. In 2009, he took a position within the U.S. Food and Drug Administration at the Institute of Food Safety and Health (IFSH), where his primary research focus is potential exposure to nanomaterials from food packaging.