Isotropic liquid crystal

The hydrotropic action of a dicarboxylic acid is discussed against the general features of hydro-tropic action the liquid crystal/isotropic solution equilibrium. It is shown that the hydrotropic action of the dicarboxylic acid in question, 8-[5(6)-carboxy-4-hexyl-cyclohex-2-enyl] octanoic acid, depends on its conformation at an interface. 

The second group involves polymers with three-dimensional ordering of side branches (e.g., those forming Mj-phaseXTable 5). On X-ray patterns of these polymers 3-4 narrow reflexes at wide angles are observed. As a rule, the authors define this type of structure as crystalline, or ascribe a smectic type of structure, characteristic for ordered smectics in SE or SH phases. The heats of transition from anisotropic state to isotropic melt are usually small and do not exceed the heats of transition smectic liquid crystal — isotropic melt . The similarity of structural parameters of three-dimensionally ordered smectics and that of crystalline polymers of the type here considered, make their correct identification quite a difficult task. 

The areas bounded by the curves represent the conditions for the stable existence of the four single phases, solid crystals, liquid crystals, isotropic liquid, and vapour. 

In this modified Flory model, the liquid crystal-isotropic transition of rods in a solution occurs at... 

Table I. Liquid Crystal/Isotropic Liquid Transition Temperatures...

Fig. 7. Schematic representation of a liquid crystal-isotropic phase diagram for rigid rods in solution.

So far, the role of phase separation in gelation has been limited to polymers which are regarded as flexible in solution. Thermoreversible gels can be formed from solutions of many rod-like polymers. " Miller et have reviewed the phase separation and networks formed by some rod-like polymers. The nature of the restoring force in such networks of rods must clearly be different from that of a rubber-like, flexible polymer network. However, that network formation occurs via a phase separation remains a possibility. Flory has developed a detailed theory for the liquid crystal-isotropic phase behaviour of rod-like particles in a diluent. 

Wee EL, Miller WG (1971) Liquid crystal-isotropic phase equilibriums in the system poly (y-benzyl a-L-glutamate)-methylformamide. J Phys Chem 75 1446-1452... 

Arguments for the minimal model system being the traveling cholesteric liquid crystal-isotropic liquid phase boundary are given in this section. The sample is prepared so that the length scale imposed on it by the non-equilibrium driving forces is comparable to the cholesteric liquid crystal s equilibrium length, its pitch. In a pattern formation context, knows time ... 

The first Broken Symmetry of Life, we identified with a liquid crystal-isotropic liquid transition. Something (i.e., the liquid crystal order parameter) emerges from nothing, the primordial soup. 

Smectic phase Liquid crystal Isotropic solution... 

Ordered crystals Disordered crystals Liquid crystals Isotropic liquid... 

The bulk of such polymers shows the characteristic phases of liquid crystals (isotropic, nematic and smectic). It raises the following problem how is the polymer backbone inserted inside the mesomorphic molecules ... 

Li JL, Crandall KA, Chu P, Percec V, Petschek RG, Rosenblatt C (1996) Dendrimeric liquid crystals isotropic—nematic pretransitional behavior. Macromolecules 29 7813-7819 Lin YG, Winter HH (1991) High-temperature recrystallization and rheology of a thermotropic liquid crystalline polymer. Macromolecules 24 2877-2882 Lin Q, Yee AF (1994) Elastic modulus of in-situ composites of a liquid crystalline polymer and polycarbonate. Polym Compos 15 156-162... 

Liquid crystal Isotropic I HYPAM3-DS100 HYPAM4-DS100 HYPAM5-DS100... 

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