Homeotropic orientation of nematic liquid crystals induced by dissolving polypropyleneimine dendrimer having peripheral mesogens
نویسندگان
چکیده
منابع مشابه
Homeotropic alignment of nematic liquid crystals with negative dielectric anisotropy
We report here uniform and defect-free homeotropic alignment of nematic liquid crystal having negative dielectric anisotropy (Deo0) on cleaned substrates, which can be changed to bright state (homogeneous alignment) by applying an electric field. However, non-uniformity in the bright state would not be desirable for display devices. Therefore, silane treated and gently rubbed substrates have be...
متن کاملTemperature dependence of surface orientation of nematic liquid crystals
-The mixed splay bend curvature elastic constant Kj~ of nematics is shown to be proportional to S, the modulus of the quadrupolar orientational
متن کاملNematic stability of discotic liquid crystals with orientation-dependent interactions.
Technological applications of discotic nematogens are limited by the robustness of the columnar phases. This investigation employs Monte Carlo simulations to explore the potentiality of tailoring specific interactions of either stacking or peripheral type in order to enhance nematic stability. It is concluded that the nematic phase is favored for discotic particles systems with homogeneous or w...
متن کاملHomogeneous and Homeotropic Alignment of Bent-Core Uniaxial and Biaxial Nematic Liquid Crystals
The effect of well-established homeotropically and homogeneously aligning polyimides, developed for calamitic liquid crystals, on the alignment of the nematic phases of bent-core mesogens was investigated using polarizing optical microscopy and conoscopy. Two polyimides, the homogeneously aligning SE7792 and the homeotropically aligning S659, were used to align three bent-core mesogens. Two of ...
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 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: Optical Materials Express
سال: 2014
ISSN: 2159-3930
DOI: 10.1364/ome.4.000934