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Light Scattering Near the Shear-Induced Critical Point in Nematic Liquid Crystals

Published online by Cambridge University Press:  25 February 2011

Peter D. Olmsted
Affiliation:
Exzon Research and Engineering Company, Rt. 22 E, Clinton Twp., Annandale, NJ 08801
Paul Goldbart
Affiliation:
Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana IL 61801
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Abstract

We study linear fluctuations about the steady states of thermotropic liquid crystals under planar sheax flow. Near the non-equilibrium critical point we find a single critical mode whose singular behavior at the critical point may be selectively probed by polarized light scattering. This critical mode is a combination of both amplitude and orientation fluctuations of the order parameter, which distinguishes it from conventional Ising-like critical modes, which are purely amplitude fluctuations. There are at least two distinct signatures of the critical point, depending on whether the critical strain rate is in the (material-dependent) strong or weak shear regimes.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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