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Mechanical model study of relationship of molecular configuration and multiphase in liquid crystal materials 总被引:3,自引:0,他引:3 下载免费PDF全文
A mechanical model of liquid crystals (LCs) is applied to
study the polymorphism of homologous series of terphenyl compounds. With
a semi-experimental molecular orbit method, we calculate the moment of inertia
which represents the rotation state to describe the phase transition
temperature obtained from experimental data. We propose a novel
explanation of the phase sequence or polymorphism of LC materials using
the two key
parameters, the moment of inertia and critical rotational velocity. The effect
of molecular polarity on the appearance of liquid crystalline is also discussed. 相似文献
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Temperature dependence of ratio between dielectric anisotropy and order parameter in fluorinated nematic liquid crystals 下载免费PDF全文
Temperature dependence of ratio between dielectric anisotropy and order parameter of fluorinated nematic liquid crystal is investigated by using a semi-empirical molecular orbital package that can accurately calculate an angle between molecular dipole moment and long axis. We optimize the molecular conformations with three semi-empirical Hamiltonians AM1, PM3 and PM5, and then make a comparison between computational results and experimental measurements. It is shown that the results obtained from AM1 method are in good agreement with the measurements. The present study offers an applicable method to predict the dielectric properties of liquid crystal material. 相似文献
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