High-resolution x-ray study of nematic–smectic-Aand smectic-A–reentrant-nematic transitions in liquid-crystal–aerosil gels
نویسندگان
چکیده
منابع مشابه
High-resolution x-ray study of nematic-smectic-A and smectic-A-reentrant-nematic transitions in liquid-crystal-aerosil gels.
We have studied the effects of quenched random disorder created by dispersed aerosil nanoparticle gels on the nematic to smectic- A (N- SmA ) and smectic- A to reentrant nematic ( SmA -RN) phase transitions of thermotropic liquid-crystal mixtures of hexyloxycyanobiphenyl (6OCB) and octyloxycyanobiphenyl (8OCB). These effects are probed using high-resolution synchrotron x-ray diffraction techniq...
متن کاملHigh-resolution x-ray study of the nematic-smectic-A and smectic-A-smectic-C transitions in liquid-crystal-aerosil gels.
The effects of dispersed aerosil nanoparticles on two of the phase transitions of the thermotropic liquid-crystal material 4-n-pentylphenylthiol-4(')-n-octyloxybenzoate (8;S5) have been studied using high-resolution x-ray diffraction techniques. The aerosils hydrogen bond together to form a gel which imposes a weak quenched disorder on the liquid crystal. The smectic-A fluctuations are well cha...
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High-resolution ac calorimetry has been used to study the nematic to smectic- A (N-SmA) phase transition in the liquid crystal octylcyanobiphenyl (8CB) confined in aligned colloidal aerosil gels. A stable and robust nematic alignment was achieved by repeated thermal cycling of the samples in the presence of a strong uniform magnetic field. In some ways (such as transition temperature and integr...
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A Chen-Lubensky energy is used to investigate phase transitions from chiral nematic to smectic C* and smectic A* liquid crystal phases. We consider a liquid crystalline material Ω confined between two parallel plates, where the dimensions of Ω are assumed to be large relative both to the width of a smectic layer and the material’s chiral pitch. We take boundary conditions so that the smectic ph...
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We report the results of a synchrotron x-ray reflectivity study of bulk liquid-crystal surfaces that are coated by thin wetting films of an immiscible liquid. The liquid-crystal subphase consisted of the nematic or isotropic phase of 4-octyl- 4;{'} -cyanobiphenyl (8CB), and the wetting film was formed by the fluorocarbon perfluoromethylcyclohexane (PFMC), a volatile liquid. The thickness of the...
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ژورنال
عنوان ژورنال: Physical Review E
سال: 2008
ISSN: 1539-3755,1550-2376
DOI: 10.1103/physreve.77.031702