Dresden 2006 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 10: POSTER Nonequilibrium Phenomena in Soft Condensed Matter
CPP 10.2: Poster
Dienstag, 28. März 2006, 17:00–19:00, P3
Global homogeneity of non-cubic bicontinuous space partitions — •Gerd E Schroeder1, Andrew Fogden2, and Stephen T Hyde1 — 1Applied Maths, Research School of Physical Sciences, Australian National University, 0200 Canberra, Australia — 2Institute for Surface Chemistry, P.O. Box 5607, SE-11486 Stockholm, Sweden
Infinite periodic minimal surfaces (IPMS) form the structural basis of cubic phases in copolymer, lipid or surfactant self-assemblies. Although few non-cubic equilibrium phases have been reported to date, there are compelling reasons to study non-cubic IPMS: first, they offer possible transition structures between bicontinuous cubic phases. Second, the reason why soft systems (that favour homogeneity but not explicitly symmetry) exhibit phases of cubic symmetry is still uncertain.
We use the concept of medial surfaces to quantify packing homogeneity, i.e. variations of the channel radius within the structure [1]. This analysis is carried out on IPMS families that are degradations of the cubic P, D and G surfaces (the rPD, rG, tG, tD tP, and H).
We show that the cubic G and D are locally maximally homogeneous, whereas the cubic P has at least one relative that is more homogeneous. We discuss the implications for molecular self-assembly (chain stretching), and compare this result to analyses of curvature fluctuations [2].
[1] A. Fogden, S.T. Hyde, Eur. Phys. J. B 7, 91–104 (1999)
[2] G.E. Schröder, S.J. Ramsden, A.G. Christy, S.T. Hyde, Eur. Phys. J. B 35, 551–564 (2003)