Dresden 2006 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 3: Polymer Materials
CPP 3.9: Vortrag
Montag, 27. März 2006, 12:15–12:30, ZEU 114
A non-cubic network phase in ABC copolymers via e−-tomograpy — •Gerd E Schroeder1, Stephen T Hyde1, Hermis Iatrou2, Nikos Hadjichristidis2, Satoshi Akasaka3, and Hirokazu Hasegawa3 — 1Applied Maths, Research School of Physical Sciences, Australian National University, 0200 Canberra, Australia — 2Chemistry Department, University of Athens, Panepistimiopolis, Zografou 15771, Athens, Greece — 3Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 Japan
We report the discovery of a novel bicontinuous tetragonal phase in the linear ABC triblock terpolymer system polystyrene, polyisoprene and polydimethylsilocane. The data is consistent with spacegroup Fddd and is distinctly non-cubic. The channel topology of the mesophase is distinct from the cubic Gyroid and Diamond mesophases. It consists in 2 identical intertwined labyrinths with 3- and 4-connected nodes. Our mesophase differs from an earlier report of a copolymer phase (also in a linear terpolymer system) with the same spacegroup by Bates et al, who deduced a single channel morphology, based on TEM and SAXS data [1]. Our proposal is based on 3D e−-tomography data. The channel geometry is identified via a medial surface (MS) algorithm. The MS is a generalised channel graph consisting in surface patches rather than line segments and is, in contrast to line graphs, a complete descriptor of both topology and geometry.
[1] T. Epps, E. Cochran, T. Bailey, R. Waletzko, C. Hardy, and F. Bates, Macromolecules 37, 8325–8341 (2004)