Berlin 2008 – wissenschaftliches Programm
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SYSA: Symposium Tayloring Organic Interfaces: Molecular Structures and Applications
SYSA 5: Poster Session SYSA
SYSA 5.3: Poster
Dienstag, 26. Februar 2008, 14:30–20:00, Poster A
Crystallization of Ferroelectric PVDF-TrFE in Cylindrical Nanopores — •Nitin Shingne1,2, Markus Geuß2, Ulrich Gösele2, Martin Steinhart2, and Thomas Thurn-Albrecht1 — 1Department of Physics, Martin Luther University, Hoher Weg 8, D-06120, Halle — 2Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120, Halle
Using differential scanning calorimetry and wide angle X-ray scattering we studied the crystallization and melting as well as the paraelectric to ferroelectric phase transition in templated 1D nanostructures of Polyvinylidenefluoride-co-trifluroethylene P(VDF-TrFE). Self-ordered porous alumina membranes served as templates. Previous studies on poly(vinylidenefluoride) have shown that the crystal orientation in the nanostructures is controlled by the kinetics of crystallization and can lead to strong orientation phenomena. Similar texture effects are observed for the copolymer studied here which can be understood in detail by taking into account that crystal growth occurs in the high temperature hexagonal phase. In all cases studied it was observed that the molecular chain axis, i.e. the c-axis, is oriented perpendicular to the long axis of the nanopores. In particular, for the copolymer the (110) lattice planes are oriented parallel to the template surface. At room temperature, the dipoles in the ferroelectric phase are preferentially oriented at an angle of 30° with respect to the long axis of the pores. Therefore, strong longitudinal polarization is present in the native nanofibers or is accessible by poling.