Modeling of molecular reorientation in nematic liquid crystals
نویسندگان
چکیده
منابع مشابه
Molecular reorientation of a nematic liquid crystal by thermal expansion
A unique feature of nematic liquid crystals is orientational order of molecules that can be controlled by electromagnetic fields, surface modifications and pressure gradients. Here we demonstrate a new effect in which the orientation of nematic liquid crystal molecules is altered by thermal expansion. Thermal expansion (or contraction) causes the nematic liquid crystal to flow; the flow imposes...
متن کاملOptical reorientation of nematic liquid crystals in the presence of photoisomerization
The optical reorientation of nematic liquid crystals doped with azo dyes is studied. It is shown that in the presence of absorption both the trans and cis isomers enhance significantly the optical torque; they contribute, however, with opposite signs to the net enhancement and tend to cancel each other’s effect. The anomalous angular dependence of optical reorientation reported by Zolotko et al...
متن کاملA molecular theory of surface tension in nematic liquid crystals
The surface tension at the free surface of a nematic liquid crystal is computed using the Fowler-Kirkwood-Buff approximation to the interface, and a mean field approximation to the molecular pair distribution function. It is found for a Van der Waals interaction between molecules that : a) the molecules always prefer an orientation in the plane of the surface; b) there is a gap at the nematic-i...
متن کاملNematic Liquid Crystals: Defects
There are two types of defects in the uniaxial nematic F phase: line defects (disclinations) and point defects (hedgehogs and boojums). These are reviewed at three levels: (i) experimental observations; (ii) topological classification; and (iii) curvature elasticity. The reader is referred to the textbooks on liquid crystals (Chandrasekhar 1992, de Gennes and Prost 1993), defects (Kltman 1983),...
متن کاملDefects in Nematic Liquid Crystals
Defects in liquid crystals are discontinuities in order parameter. In nematic liquid crystals (NLC) two types of stable defects exist: disclination lines and point defects. Defects formation depends on isotropic to nematic phase transition while their stability depends strongly on confining surface properties, surface geometry and presence of external field. Classical Frank’s model of director ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Photonics Letters of Poland
سال: 2016
ISSN: 2080-2242
DOI: 10.4302/plp.2016.1.04