Chemically bonded phases liquid crystalline

In contrast to polypeptides that have many possible conformations, poly(hexyl isocynate) is known to have a stiff rodlike helical conformation in the solid state and in a wide range of solvents, which is responsible for the formation of a nematic liquid crystalline phase.45-47 The inherent chain stiffness of this polymer is primarily determined by chemical structure rather than by intramolecular hydrogen bonding. This results in a greater stability in the stiff rodlike characteristics in the solution as compared to polypeptides. The lyotropic liquid crystalline behavior in a number of different solvents was extensively studied by Aharoni et al.48-50 In contrast to homopolymers, interesting new supramolecular structures can be expected if a flexible block is connected to the rigid polyisocyanate block (rod—coil copolymers) because the molecule imparts both microphase separation characteristics of the blocks and a tendency of rod segments to form anisotropic order. 

Two basic requirements for superconductivity are the pairing of electrons and phase coherence. Both of these can be satisfied in highly anisotropic arrays of loosely associated double bonds which are not directly chemically bonded as further association due to extra electrons would then be impossible. These criteria seem to be fulfilled by proper liquid crystalline state of matter. 

ELECTRICAL CONDUCTIVITY AND CHEMICAL BONDING IN CRYSTALLINE, GLASSY, AND LIQUID PHASES ... 

A qualitative quantum-mechanical treatment Is given of the mechanism of chemical bonding in crystalline, glassy, and liquid phases. It ls shown that the electrical properties of some substances can be explained on the basis of a relationship between the number of valence electrons, the number and kind of orbitals, and the overlap of the orbitals. 

It cannot be stressed enough that in PLCs the flexible and the LC sequences form separate phases. Since these two types of sequences are typically coimected by primary chemical bonds, then each predominantly flexible phase contains a certain number of LC sequences such a phase is called a LC-poor phase or simply a flexible matrix. Each predominantly liquid crystalline phase, called a LC-rich phase or an island [19] contains necessarily a certain number of flexible sequences. Thus, even a pure PLC— not a blend— typically contains at least two phases. This fact was discussed already in 1980 by Menczel and Wtmderlich [40] who using differential scanning calorimetry (DSC) observed two glass transition temperatures, one for the flexible and one for the LC-rich phase their subsequent more extensive studies confirmed this conclusion [41]. 

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