Planar configurations, nematics

Figure 9. Defect line produced in a nematic liquid by two parallel glasses so treated that they have planar anchoring conditions, with two mutually perpendicular easy directions. The discontinuity line is either attached to the upper glass (a) or to the lower one (c), or lies in the bulk (b). (d) The three localizations of the defect thread along a path aASp, with a planar configuration in the bulk, (e) A nonpla-nar distribution of directors is more likely.

Our illustration of pretransitional behavior in frustrated NLC systems is restricted to fluctuations in the biaxial structure of the hybrid nematic cell with equal strengths of homeotropic and planar anchorings. The detailed analysis of the pretransitional dynamics of all five degrees of freedom around the bent-director configuration is somewhat more complicated because of the nonuniformity of the base tensors. 

Fig. 1 Field-driven director configurations in (a) a nematic liquid (conventional Fredericks effect) and (b) a nematic elastomer slab floating in liquid between rigid electrodes. They initially have a uniform planar orientation before imposing field E in the direction shown by the arrow. In (a), the director at the surfaces are anchored, and the rotation angle of director has a finite distribution along the field axis, with the maximum at the middle layer of the cell. The recovery force for the director originates from the Frank elasticity. In (b), the director is capable of uniform rotation under electric fields, and the Frank elasticity plays no role in the recovery force...

Figure 19. Schematic lepresentation of nematic director configurations for the (a) planar radial, (b) planar polar, and (c) escaped radial nematic structures in microcylinders [215].

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