MATERIALS  SEMINAR
Department of Materials Science & Engineering
Tuesday March 5, 2019
2:15 – 3:15 ~ SERF 307
Please join us for refreshments at 2:10

"Processing High Solids Suspensions via Additive Manufacturing & Electrospinning"

Speaker: Dr. Blair Brettmann-Assistant Professor
Chemical & Biomolecular & Materials Science Engineering
Georgia Institute of Technology-Atlanta, GA

Abstract:
Materials with high particle loadings are important for many applications: in many cases the particles provide the desired functionality and the polymer acts to bind them together into a shape, so maximizing particle content is required. As new processing technologies become more prevalent, such as 3D printing and continuous manufacturing (e.g. for pharmaceuticals and energetics), low binder content has introduced challenges, particularly due to the high viscosities encountered in highly loaded systems. Understanding the rheology and the effect of chemistry and molecular interactions on the processability is of great importance to the field. We have focused primarily on two processing technologies: additive manufacturing (AM, direct ink writing 3D printing) and electrospinning. For energetic materials, AM provides a unique opportunity to fabricate energetic materials in geometries that are traditionally difficult or impossible to manufacture via subtractive means, in particular engineered lattice and cellular structures for wave focusing or energy dissipation. The high particle loadings (> 60 vol%) required for these materials provide significant challenges to processing, particularly for direct ink writing, which requires precise control of the material in a flow condition. We study the heterogeneities in AM energetic materials, examining the material mixing and rheology as a function of solid loading, flow in the nozzle and 3D printing of the mixtures. In a parallel project for preparing highly functional nanofiber mats, we have developed the electrospinning processing to prepare nanofibers containing high loadings of particles, again, with particular attention to rheology and molecular level behavior.

Biography:
Blair Brettmann received her B.S. in Chemical Engineering at the University of Texas at Austin and her Ph.D. in Chemical Engineering at MIT. Her PhD focused on continuous manufacturing of pharmaceuticals. Following her Ph.D., Dr. Brettmann was a Senior Research Engineer at Saint-Gobain, where she worked on solution deposited coatings, including leading a project to develop a new IR-absorbing window film, which has since been commercialized. Later, Dr. Brettmann served as a postdoctoral researcher in the Institute for Molecular Engineering at the University of Chicago with Matt Tirrell before joining Georgia Tech in January 2017. Her research focuses on linking molecular to micron scale phenomena to processing and multicomponent complex mixtures to enable rapid and science-driven formulation and product development.