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Undulation instability in smectic A liquid single crystal elastomers
Author(s) -
Weilepp Jochen,
Brand Helmut R.
Publication year - 1998
Publication title -
macromolecular theory and simulations
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 56
eISSN - 1521-3919
pISSN - 1022-1344
DOI - 10.1002/(sici)1521-3919(19980101)7:1<91::aid-mats91>3.0.co;2-6
Subject(s) - instability , liquid crystal , elastomer , wavelength , light scattering , materials science , scattering , optics , stress (linguistics) , condensed matter physics , crystallography , chemistry , molecular physics , physics , composite material , mechanics , linguistics , philosophy
We present a macroscopic model for the behavior of smectic A liquid single crystal elastomers (LSCEs) under an external dilatory stress thus investigating the elastomeric analogue of the undulation instability in low molecular weight (LMW) smectic A liquid crystals. We show that the critical wavelength λ c of the expected undulation pattern is given by an expression quite similar to that obtained for LMW smectic A phases. This result provides a possible explanation for the strong light scattering (high turbidity) observed by Nishikawa et al. very recently in thick samples of a smectic A LSCE above a certain threshold stress applied parallel to the layer normal in the experiments. We find that, in contrast to the critical wavelength λ c , the threshold dilatation ε c is dominated by the elastic properties of the smectic LSCE. Thus – as observed in the experiments by Nishikawa et al. −ε c is found to be several orders of magnitude higher than in the LMW case.