Ferroelectrics columnar discotic

Discotic Ferroelectrics. Columnar meso-phases with chiral disk-shaped molecules whose normals are tilted with respect to the column axis also manifest ferroelectric switching [217]. In such phases the direction of the spontaneous polarization is perpendicular to both the column axis and to the normal to the molecular disks. The tilt of the disk forms a helix with its axis oriented along the columns. In an amphiphilic... 

Foerster transfer rate, columnar discotics 790 formaldehyde, reagents 716 formulations, chiral nematics 305 fourth rank tensor, ferroelectrics 614 frame rate control. Gray levels 207 frame time, TN displays 205 Frank constants... 

Discotic and bowl-shaped molecules that form columnar phases, (a) Hexa-alkanoate [R=CH3-(CH2) -2C00-] of triphenylene (b) hexa-noyloxy-tribenzocyclononene, which forms a polar pyramidlc phase (c) l,2,5,6,8,9,12,13-octakis-((S)-2-heptyloxy) dlbenzo[e,l]pyrene, which has chiral therminal chains and forms tilted ferroelectric columnar liquid crystal. ... 

Spontaneous polarisation can also be observed for chiral discotic metallomesogens forming columnar mesophases, when the chiral molecules are tilted with respect to the column axis. The tilt induces a dipole moment within the plane of the molecule. A net macroscopic polarisation can be obtained for rectangular columnar phases with Cz or P2i symmetry. Serrano and Sierra reported on ferroelectric switching in the columnar mesophase for chiral /3-diketonate complexes (Figure 2.52). ... 

The main objective of this chapter is to review and outline the research studies and perspectives on liquid crystalline elastomers and LC anisotropic networks, with emphasis on recent interesting innovations on network-stabilized ferroelectric LC (FLC) gels, discotic columnar networks, and self-assembly hydrogen-bonded LC network. We will also present hybrid networks based on ladderlike polysiloxanes that have been developed in our group as advanced functional film materials. 

More recently, chiral discotic materials that exhibit tilted columnar mesophases have attracted attention because of their potential for ferroelectric switching. A spontaneous polarisation is generated because of the restriction in rotation of the peripheral chiral chains. 

Columnar phases can be ferroelectric if the discotic molecules are chiral and tilted with respect to the column axis [74]. From sym-... 

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