scholarly journals Orientational order parameter of liquid crystalline mixtures - A birefringence study

2018 ◽  
Vol 9 (6) ◽  
pp. 735-740 ◽  
Author(s):  
Shahina ◽  
C.M. Subhan ◽  
S. Rangappa ◽  
K. Fakruddin
Keyword(s):  
Order Parameter ◽  
Liquid Crystalline ◽  
Orientational Order ◽  
Orientational Order Parameter

scholarly journals DNA Origami Nano-Sheets and Nano-Rods Alter the Orientational Order in a Lyotropic Chromonic Liquid Crystal

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1695
Author(s):  
Bingru Zhang ◽  
Kevin Martens ◽  
Luisa Kneer ◽  
Timon Funck ◽  
Linh Nguyen ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Order Parameter ◽  
Liquid Crystalline ◽  
Orientational Order ◽  
Dna Origami ◽  
Nano Particles ◽  
Width Ratio ◽  
Disodium Cromoglycate ◽  
Orientational Order Parameter ◽  
Nano Rods

Rod-like and sheet-like nano-particles made of desoxyribonucleic acid (DNA) fabricated by the DNA origami method (base sequence-controlled self-organized folding of DNA) are dispersed in a lyotropic chromonic liquid crystal made of an aqueous solution of disodium cromoglycate. The respective liquid crystalline nanodispersions are doped with a dichroic fluorescent dye and their orientational order parameter is studied by means of polarized fluorescence spectroscopy. The presence of the nano-particles is found to slightly reduce the orientational order parameter of the nematic mesophase. Nano-rods with a large length/width ratio tend to preserve the orientational order, while more compact stiff nano-rods and especially nano-sheets reduce the order parameter to a larger extent. In spite of the difference between the sizes of the DNA nano-particles and the rod-like columnar aggregates forming the liquid crystal, a similarity between the shapes of the former and the latter seems to be better compatible with the orientational order of the liquid crystal.

Optical Study of Orientational Order Parameter in p-n-(Phenyl Benzylidene) -p-Alkyl and Alkyloxy Anilines

2011 ◽  
Vol 181-182 ◽  
pp. 75-78 ◽  
Author(s):  
B.R. Rajeswari ◽  
P. Pardhasaradhi ◽  
M. Ramakrishna Nanachara Rao ◽  
P.V. Datta Prasad ◽  
D. Madhavi Latha ◽  
...  
Keyword(s):  
Order Parameter ◽  
Liquid Crystalline ◽  
Orientational Order ◽  
Molecular Vibration ◽  
Refractive Indices ◽  
Orientational Order Parameter ◽  
Optical Study ◽  
Shaped Cell ◽  
Scaling Methods ◽  
Molecular Polarizabilities

The refractive indices measurements are carried out using a modified spectrometer connected with wedge shaped cell and also the direct measurement of birefringence,δn obtained from Newton’s rings method with an indigenous setup for the liquid crystalline compoundsp-n-(phenyl benzylidene)-p-n-alkyl and alkyloxy anilines, PBnA and PBnOA compounds. The molecular polarizabilitiy anisotropy (α||- α⊥) is calculated for these compounds from different methods such as Lippincott δ-function model, molecular vibration method, Haller’s extrapolation method and scaling methods respectively. Further, the estimation of the molecular polarizabilities αeand αoare done from the isotropic Vuks and anisotropic Neugebauer models. The order parameter directly calculated from ∆n employing the method developed by Kuczynski is compared with the order parameter estimated from the different models using molecular polarizabilities.

Orientational order parameter of some CBOnO.m liquid crystalline compounds—an optical study

2016 ◽  
Vol 641 (1) ◽  
pp. 25-36 ◽  
Author(s):  
G. K. Narasimhamurthy ◽  
C. M. Subhan ◽  
Seema Agarwal ◽  
S. Rangappa ◽  
C. V. Yalamaggadd ◽  
...  
Keyword(s):  
Order Parameter ◽  
Liquid Crystalline ◽  
Orientational Order ◽  
Orientational Order Parameter ◽  
Optical Study

Effects of Surface Conditions on Rheological Properties and Phase Orientation of Sheared LCP Melts in Nanochannels by MD Studies

2006 ◽  
Vol 532-533 ◽  
pp. 624-627
Author(s):  
Lan He ◽  
Kai Leung Yung ◽  
Yun Wen Shen ◽  
Yan Xu
Keyword(s):  
Surface Roughness ◽  
Rheological Properties ◽  
Shear Viscosity ◽  
Order Parameter ◽  
Liquid Crystalline ◽  
Orientational Order ◽  
Crystalline Polymer ◽  
Md Simulations ◽  
Isotropic Phase ◽  
Orientational Order Parameter

The rheological properties and phase orientation of liquid crystalline polymer (LCP) melts flowing in a nanochannel with different surface roughness are investigated by molecular dynamics (MD) simulations. Simulation results show the surface roughness has great impact on the rheological properties and phase orientation of LCP melts in the nanochannel (cross section is 12nm). As the amplitude of serrations increases, the shear viscosity increases nonlinearly and the value of orientational order parameter decreases. When the serration amplitude is larger than 1.1nm, a phase transition (from nematic to isotropic phase) of LCP melt happens, which makes flowing in nanochannels more difficult. On the other hand, the influence of serration period on the shear viscosity and orientational order parameter are found not so obvious. Findings in this study will be helpful for injection molding plastic products with nanofeatures.

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