Nano Micromechanics Design and Fabrication of Polymer Nanocomposites

Wednesday, November 4, 2009
4:00 - 5:15 PM
190 Holden Hall

Dr. Sarah Baxter
University of South Carolina
Columbia, South Carolina

Polymer nanocomposites offer extraordinary promise for new material systems with specifically designed properties. A key challenge limiting the ability to fully realize this promise is the necessity of generating a well-dispersed nanophase. Without distinct and deliberate spatial separation, the composite material will not exhibit the properties that are due to the nanoparticles’ nano-size. Traditional polymer processing techniques, e.g. extrusion, or flow controlled stirring in of filler nanoparticles into a liquid polymer solution, casting, and more novel approaches such as chemical self-assembly, lithographic techniques, and growth and dispersion block co-polymer assembly, are starting to address these issues for specific material systems. However, the resulting composite microstructures are largely uncontrolled; producing nano-filled materials, but rarely spatially engineered or designed composites. To realize the predicted nanophase properties requires the ability to design and fabricate hierarchical microstructures.

In this work we demonstrate a synergistic sequence of modeling and experimental work. The modeling work includes two aspects; first efforts to capture the effects of scale in the mature models of micromechanics, making them nano-valid; and second, setting up simple models of nano-dynamics to help guide the experimental work. The experimental work explores the use of electric and magnetic force fields as handles to manipulate metallic nanorods into designed microstructures. Optimization of these methods holds the potential to produce both thin film polymer nanocomposite ribbons of aligned rods, circular domains of radially aligned rods or specific, anisotropic, laminate microstructures.

Professor Sarah Baxter is mostly from Colorado. She received an MS in Applied and Computational Mathematics from the University of Minnesota in 1991 and her PhD., in Applied Mathematics from the University of Virginia, in Applied Mechanics she was appointed to the faculty of the University of South Carolina. Her research interests are in the mechanics of heterogeneous materials, biomechanics, the micromechanics of composites, and probabilistic micromechanics.

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