Isotropic phases, liquid crystal-supercooled

This can be also illustrated as follows a fatty man can be surrounded by 4 - 5 closely-packed fat men. But the same man can be surrounded even by 10 slim men. The latter can parallel the increasing dimensionality of space for the fat man. Consequently, the elongation of fluctuations due to the action of the strong electric field in the homogeneous phase of binary mixtures of limited miscibility is equivalent to increased dimensionality d = A. The uniaxial symmetry is natural also for the isotropic phase nematic liquid crystals. It may be considered for supercooled nitrobenzene due to intermolecular interactions (Fig. 5). ... 

In the case of a supercooled liquid, spontaneous formation of nuclei or crystal growth centres also takes place. Since, however, an anisotropic phase, with definite molecular arrangement, must now be formed from an isotropic phase, the number of nuclei formed in a given time per unit mass of the substance will be less than in the case of transformations between isotropic phases. 

C. Similarity in Orientational Dynamics Between the Isotropic Phase of Liquid Crystals and Supercooled Liquids... 

Liquid crystals can be divided into two main classes those similar to the cho-lestrayl derivatives, whose liquid crystalline phases are formed when the pure compound is heated, arc called thermotropicy and those where the hquid crystalline phase forms when the molecules are mixed with a solvent are referred to as lyotropic. The thermotropic class also includes enantiotropic types, whae the liquid crystalline phases can be seen on both the heating and the cooling cycles, and monotropic types, where the mesophase is stable only on supercooling from the isotropic melt. 

The way, or sequence, in which thermotropic transitions occur is defined in the following ways. The liquid crystal to isotropic liquid transition is called the clearing or isotropization point, and this transition, like those between liquid crystal phases, is essentially reversible and occurs with little hysteresis in temperature. The melting point of a material is usually a constant, but the recrystallization process can be subject to supercooling. Mesophases formed on the first heating cycle of a material are thermodynamically stable, and are called enantiotropic phases, whereas phases that are formed below the melt point on cooling cycles, and are revealed... 

On cooling the nematic phase can be supercooled more than 25. Smectogenic phases may exhibit a whole sequence of liquid crystal phases. An example of that is terephtal-dibutyl-aniline (TBBA). In addition to two crystalline modifications and the nematic (N) and isotropic phase (I) there are five different smectic phases. 

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