0602473_Cebe

1. Constraints in Semicrystalline Polymers During the Transition from the Liquid to the Solid StatePeggy Cebe, Tufts University, DMR 0602473 Background: Polymer composites that contain nano-scale inclusions are used in advanced applications including the automotive, aerospace, and electronics industries. We are using polyhedral oligomeric silesquioxane (POSS) to mix into polymer nano-fibers to form nanocomposites. The additive serves as a molecular level of reinforcement to the polymer host, making the host material stronger. Mechanical and electrical properties as well as thermal stability of polymer materials can be highly improved by incorporation of a very small amount of the additive. Objective:Using electrospinning, we form polymer nanocomposite fibers of PBT, poly(butylene tereph-thalate) with POSS. PBT is an industrially important polymer used in packaging, electrical, automotive, and tissue engineering due to its excellent chemical resistance, thermal stability, robust solvent resistance, and spinnability. Results: Adding POSS into PBT electrospun fibers leads to an increase in the fiber diameter and fiber alignment. POSS does not affect the ability of PBT to crystallize in annealed fibers. Figure: (left) Scanning electron microscopy shows electrospun fibers of PBT (top) and PBT with 3% POSS (bottom). (right) Corresponding X-ray diffraction of annealed fibers showing typical pattern of crystalline PBT. Data from an International Collaboration between Tufts U. (T) and U. Genoa (G). Erika Simona Cozza (G), Qian Ma (T), Orietta Monticelli (G), Peggy Cebe (T). Submitted to European Polymer J. (2012).

2. Constraints in Semicrystalline Polymers During the Transition from the Liquid to the Solid StatePeggy Cebe, Tufts University, DMR 0602473 c a b Providing research and educational enrichment for students: (a-c.) Tufts Physics majors perform research in the Cebe Lab: a.) Ellen Garven uses the infrared spectrometer to study collagen basement membranes; b.) Amelia Downs prepares a sample for thermal analysis. c.) Kevin Li use the polarizing optical microscope to study poly(lactic acid) fibers. Outreach: d.) Prof. Cebe (second from right) gave a lecture at the University of Genoa, Italy, on providing research opportunities for deaf and hard of hearing students. She is shown with colleagues (l-r) Erika Simona Cozza, Orietta Monticelli, and Giancarlo Alfonso. d