Publication Title

Physical Review Letters

Publication Date

12-4-2009

Document Type

Article

DOI

10.1103/PhysRevLett.103.237803

Keywords

banana-shaped molecules, shear-flow, viscoelastic solutions, Tetrahedratic phase, Nematic transition, achiral molecules, isotropic-phase, complex, polymers, Mesogens

Disciplines

Physics

Abstract

We have found that bent-core liquid crystalline materials show exceptionally large intrinsic flow birefringence in their isotropic liquid phase. This effect is more than 100 times larger than typical values measured for low molecular weight liquid crystals. The specific flow birefringence (i.e., normalized by the flow viscosity) is an order of magnitude larger than in both side-chain polymeric as well as low molecular weight liquid crystals. We propose that this large enhancement for bent-core compounds may be attributed to nanoscale smecticlike clusters that persist above the nematic-isotropic transition temperature, and shear align under shear flow; however, this mechanism has not yet been definitively confirmed.

Comments

Copyright 2009 American Physical Society. Available on publisher's site at http://dx.doi.org/10.1103/PhysRevLett.103.237803


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