Liquid crystal polymer discotic shape

There are several different phases in thermotropic liquid crystals. The structural nature of mesophases is influenced by the molecular shape and therefore depends on whether the liquid crystal is formed by rod-like or disc-like molecules. Thermotropics of rod-like molecules may be divided into two main categories nematic and smectic phases. There exist many types of smectic phases, labeled as 5, 5b, S /. When an ordered solid of a liquid crystal melts (see Fig. 1.1), it may melt into a nematic phase or a smectic A phase. Upon further heating, it eventually turns into an isotropic liquid. First, classical thermotropic liquid crystals are described, and then a group of more exotic liquid crystals like discotic thermotropics, lyotropics, and liquid crystalline polymers. 

Examples of (a) calamitic [65], (b) discotic [28], and (c) banana-shape [30] mesogenic structures of liquid crystal polymers. 

Fig. 5.20. Some simple topologies of polymer liquid crystals (PLCs) derived from calamltic and discotic mesogenic cores main-chain PLCs, copolymers with core and flexible spacer alternating side-chain PLCs with mesogenic cores attached by flexible spacers to the main chain of a conventional polymer and dendritic (or star-shaped) stmctures with mesogens emanating from a central core via flexible spacers.

Silicate layers show an extreme anisotropic shape, strong interactions due to their polar-ionic character, and high stiffness compared to conventional polymers. These extraordinary properties resulted in extraordinary phase, orientation, and rheological behavior that is probably comparable discotic or sanidic liquid crystals. Shear rates, which are common in the standard or industrial... 

The second group comprises thermotropic polymers. The phase transitions of thermotropic liquid crystals are achieved when a determined temperature range is reached. The fundamental unit that induces structural order in this kind of polymer presents with high rigidity and anisotropic shape [26,27]. Two major subclasses can be distinguished according to this shape discotic (disc-Uke molecules) and... 

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