The effect of surface roughness of a solid substrate on its wetting by a smectic-A structure in the nematic phase of a liquid crystal

1999 ◽  
Vol 41 (2) ◽  
pp. 306-312 ◽  
Author(s):  
L. V. Mirantsev ◽  
A. V. Zakharov ◽  
V. G. Korsakov
2009 ◽  
Vol 36 (2) ◽  
pp. 165-172 ◽  
Author(s):  
Guohui Pan ◽  
Yubo Cao ◽  
Renwei Guo ◽  
Huicong Cheng ◽  
Zhou Yang ◽  
...  

2008 ◽  
Vol 35 (9) ◽  
pp. 1151-1160 ◽  
Author(s):  
Guohui Pan ◽  
Lilong Yu ◽  
Hongbin Zhang ◽  
Jinbao Guo ◽  
Renwei Guo ◽  
...  

Author(s):  
Javad Mirzaei ◽  
Martin Urbanski ◽  
Heinz-S. Kitzerow ◽  
Torsten Hegmann

We examine for the first time how chemically and thermally stable gold nanoparticles (NPs), prepared by a silane conjugation approach, affect both the thermal and the electro-optical properties of a nematic liquid crystal (LC), when doped at concentrations ranging from 0.25 to 7.5 wt%. We find that the octadecylsilane-conjugated gold NPs stabilize both the enantiotropic nematic and the monotropic smectic-A phases of the LC host with a maximum stabilization of 2 ° C for the nematic and 3.5 ° C for the smectic-A phases for the mixture containing 1 wt% of the silanized particles. The same mixture shows the lowest values for the Fréedericksz transition threshold voltage and the highest value for the dielectric anisotropy. Generally, all NP-containing mixtures, except mixtures with NP concentrations exceeding 5 wt%, reduce the threshold voltage, increase the dielectric anisotropy and reduce both rise and decay time; the latter particularly at temperatures at least 10 ° C below the isotropic–nematic phase transition on cooling.


Soft Matter ◽  
2020 ◽  
Vol 16 (36) ◽  
pp. 8352-8358
Author(s):  
Ryan S. Preusse ◽  
Elizabeth R. George ◽  
S. Ali Aghvami ◽  
Timothy M. Otchy ◽  
Mohamed Amine Gharbi

Effect of surface topography in the creation of disclinations and the assembly of defects in a smectic A liquid crystal.


1983 ◽  
Vol 22 ◽  
Author(s):  
R. Shashidhar

ABSTRACTSome of the important results emerging from our recent investigations on liquid crystals at high pressure are presented. In particular the following topics will be discussed: i) The relation between Pm, the maximum pressure of smectic stability, and the temperature range of the nematic phase in reentrant nematogenic compounds. ii) Piezothermal studies in the vicinity of the smectic A-nematic transition in 8 OCB. iii) The effect of molecular ordering on the pressure behaviour of the nematic-isotropic transition in reentrant nematic mixtures. iv) The first observation of a multicritical point in a single component liquid crystal.


Author(s):  
K.J. Ihn ◽  
R. Pindak ◽  
J. A. N. Zasadzinski

A new liquid crystal (called the smectic-A* phase) that combines cholesteric twist and smectic layering was a surprise as smectic phases preclude twist distortions. However, the twist grain boundary (TGB) model of Renn and Lubensky predicted a defect-mediated smectic phase that incorporates cholesteric twist by a lattice of screw dislocations. The TGB model for the liquid crystal analog of the Abrikosov phase of superconductors consists of regularly spaced grain boundaries of screw dislocations, parallel to each other within the grain boundary, but rotated by a fixed angle with respect to adjacent grain boundaries. The dislocations divide the layers into blocks which rotate by a discrete amount, Δθ, given by the ratio of the layer spacing, d, to the distance between grain boundaries, lb; Δθ ≈ d/lb (Fig. 1).


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