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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 8: POSTER: Polymer Physics
CPP 8.18: Poster
Montag, 26. März 2007, 16:00–18:00, Poster B
Texture control in PVDF nanotubes — •Nitin Shingne1,2, Markus Geuß2, Lili Zhao2, Martin Steinhart2, Ulrich Gösele2, Elke Hempel1, and Thomas Thurn-Albrecht1 — 1Department of Physics, Martin Luther University, D-06120, Halle — 2Max-Planck-Institute of Microstructure Physics, D-06120, Halle
Using DSC and WAXS we studied the crystallization of poly(vinylidene fluoride) nanotubes templated inside the pores of ordered porous alumina. The crystal texture resulting from isothermal crystallization strongly depends on the crystallization temperature. We observed that crystallization at lower temperatures led to statistical orientation of the crystallites modified by growth under the conditions of 2D confinement. However, at high crystallization temperatures the 1D nanostructures shows a uniform crystal orientation with the (020)-direction pointing along the pore axes. Crystallization has to be initiated independently in each of the separated nanotubes, most likely by homogeneous nucleation. We assume that the orientation observed at low crystallization temperature reflects the random orientation of the nuclei and additionally a selection of growth direction along the pore axes, whereas at high crystallization temperatures the growth along different crystal directions seems to be highly selective leading to the well defined crystal orientation within the nanotubes. Therefore, by choosing the crystallization temperature, control of crystal orientation within the 1D nanostructures is possible. This approach could pave the way for the reversible adjustment of ferro- and piezoelectric properties of the 1D polymeric nanostructures.