Polymer composites are materials systems with two or more components where the resulting properties can be tailored by the choice and placement of the individual materials during processing. Polymers are normally poor thermal conductors, but when combined with thermally conductive nanofillers, can result in a polymer composite with desirable conductivity for applications such as microelectronic packaging, substrates for LED-lighting, and solar panel seals. Multilayer co-extrusion, a novel manufacturing technology, provides a promising route to fabricate polymer composites of desirable architecture and properties. Through rational materials design, advanced manufacturing, and structure-property measurements, this award identifies key factors that affect heat conduction in polymer composites and establishes a polymer processing approach to manufacture thermally conductive nanocomposites for applications with significant socio-economic impact. This highly interdisciplinary research provides rich education and training opportunities for students of diverse backgrounds from high-school to graduate level.
Multilayer co-extrusion processing, when combined with proper design of the precursor materials, could produce nanocomposites with desired microstructure - forming a nanofiller percolation network to enable efficient heat conduction. However, several scientific questions remain to be answered, such as optimal nanofiller characteristics, the most effective way to form percolation networks at a low filler loading, and the desired thermal contact morphology. This project aims to fill the knowledge gap through systematic studies covering the entire research loop of designing materials based on fundamental understanding of multiscale thermal transport mechanisms, tuning the manufacturing processes to achieve desired microstructures, and characterizing the thermal conductivity of the resulting composites to obtain new design insights. The collaborative study tests the central hypothesis that well-controlled multilayer co-extrusion processing can produce thermally conductive polymer composites with true percolation networks formed by direct contacts between anisotropic nanofillers and an optimal network morphology with low contact thermal resistance. This research project is a collaboration between a team that explores co-extrusion of multilayer nanocomposites to generate the desired microstructures and a team that characterizes thermal transport properties to provide insights into materials design and performance.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
