Monodomain alignment

Moreover, the monodomain-aligned films of crosslinked PLCPs show anisotropic photoinduced bending behavior [28]. As shown in Figure 7.10, the photoinduced... 

FIGURE 7.10 Anisotropic bending behavior of monodomain-aligned crossUnked PLCP... 

An aligned monodomain of a nematic liquid crystal is characterized by a single director n. However, in imperfectly aligned or unaligned samples the director varies tlirough space. The appropriate tensor order parameter to describe the director field is then... 

Zhang SM, Greenfield MA, Mata A et al (2010) A self-assembly pathway to aligned monodomain gels. Nat Mater 9 594—601... 

Instabilities caused by the anisotropy of conductivity and corresponding to a periodic deformation of the alignment of the director in a nematic monodomain under the action of a direct current or low-frequency alternating current. 

The molecular theory of Doi [63,166] has been successfully applied to the description of many nonlinear rheological phenomena in PLCs. This theory assumes an un-textured monodomain and describes the molecular scale orientation of rigid rod molecules subject to the combined influence of hydrodynamic and Brownian torques, along with a potential of interaction (a Maier-Saupe potential is used) to account for the tendency for nematic alignment of the molecules. This theory is able to predict shear thinning viscosity, as well as predictions of the Leslie viscosity coefficients used in the LE theory. The original calculations by Doi for this model employed a preaveraging approximation that was later... 

More recently Ikeda and Tsutsumi [113] have used a SCLC polymer, 49, in which all of the mesogens are photoactive, azoaryl groups. They irradiated (355 nm, Nd-YAG) surface aligned monodomain films of 49 in both the N phase at... 

Figure 25.9 Polarizing optical micrographs of the equimolar mixture of 14 and 16 in the smectic A liquid crystalline state (a) homeotropically aligned monodomain is formed on a glass substrate when the sample is cooled slowly from the isotropic state at the rate of 3° C min Inset is a conoscopic image (b) unaligned polydomains are formed on a glass substrate when the sample is cooled from the isotropic state at the rate of 20°C min ...

Figure 25.10 Schematic iiiustration of the ceiis for the anisotropic ion conductive measurements. The samples forming homeotropicaiiy aligned monodomains in the smectic liquid crystalline states are filled between electrodes.

---