Effect of Molecular Structure on Mesomorphism. 6. Non-Linear Thermal Behavior in Some Binary Liquid Crystal Systems
Most binary mesophase systems exhibit mesophase-isotropic transition temperatures which are linearly dependent on composition. There are however exceptions. Demus (1) reported non-linear behavior for some mixtures when one component was a chloro mesogen. Dave (2) found similar behavior with chloro and nitro liquid crystals and postulated a structural rationale based on dipolar characteristics of the constituent molecules. Schroeder and Schroeder (3) reported in 1968 that non-mesomorphic nitro-terminated anils enhanced (4) the smectic phase of di-n-hexyloxyazoxybenzene. These authors suggested a loose dimeric association of the nitro anils as part of a molecular explanation for this enhanced smectic phase.
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