scholarly journals Anchoring Energy for Nematic Liquid Crystals an Analysis of the Proposed Forms

1984 ◽  
Vol 39 (11) ◽  
pp. 1066-1076 ◽  
Author(s):  
G. Barbero ◽  
N. V. Madhusudana ◽  
G. Durand
Keyword(s):  
Liquid Crystal ◽  
Infinite Series ◽  
Tilt Angle ◽  
Legendre Polynomials ◽  
Fourier Expansion ◽  
Easy Axis ◽  
Practical Interest ◽  
Surface Anchoring ◽  
Functional Forms ◽  
Anchoring Energy

We analyze the proposed functional forms describing the surface anchoring energy of MBBA nematic liquid crystal. Measurements of the surface torque versus tilt angle suggest that the simple cosinus-square form is not adequate for MBBA. The generalized form in an infinite series in cosinus-square is not useful since the set of functions is not orthogonal. Analyses using the orthogonal Legendre polynomials and Fourier expansion are given. Finally we analyse the data in terms of small tilt angles compared to the easy axis, and very far from it, which are the two limits of practical interest.

Determination of the unified surface-anchoring energy of a nematic liquid crystal on a polymer substrate

1998 ◽  
Vol 72 (3) ◽  
pp. 329-331 ◽  
Author(s):  
Akihiko Sugimura ◽  
Tetsuo Miyamoto ◽  
Makoto Tsuji ◽  
Michiyoshi Kuze
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Polymer Substrate ◽  
Surface Anchoring ◽  
Anchoring Energy

scholarly journals Electrically Tuneable Optical Diffraction Gratings Based on a Polymer Scaffold Filled with a Nematic Liquid Crystal

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2292
Author(s):  
Dejan Bošnjaković ◽  
Mathias Fleisch ◽  
Xinzheng Zhang ◽  
Irena Drevenšek-Olenik
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Optical Diffraction ◽  
Polymer Scaffold ◽  
Inhomogeneous Surface ◽  
Optical Elements ◽  
Surface Anchoring ◽  
Rigorous Coupled Wave Analysis ◽  
Anchoring Energy ◽  
Rigorous Coupled Wave

We present an experimental and theoretical investigation of the optical diffractive properties of electrically tuneable optical transmission gratings assembled as stacks of periodic slices from a conventional nematic liquid crystal (E7) and a standard photoresist polymer (SU-8). The external electric field causes a twist-type reorientation of the LC molecules toward a perpendicular direction with respect to initial orientation. The associated field-induced modification of the director field is determined numerically and analytically by minimization of the Landau–de Gennes free energy. The optical diffraction properties of the associated periodically modulated structure are calculated numerically on the basis of rigorous coupled-wave analysis (RCWA). A comparison of experimental and theoretical results suggests that polymer slices provoke planar surface anchoring of the LC molecules with the inhomogeneous surface anchoring energy varying in the range 5–20 μJ/m2. The investigated structures provide a versatile approach to fabricating LC-polymer-based electrically tuneable diffractive optical elements (DOEs).

Effect of the Surface Anchoring Energy on Modeling the Defect in the Liquid Crystal Director Field

2010 ◽  
Vol 57 (4) ◽  
pp. 752-755 ◽  
Author(s):  
Bongsik Jeong ◽  
Wan-Seok Kang ◽  
Woo-Yong Joo ◽  
Seung-Yeol Hur ◽  
Hak-yong Han ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Director Field ◽  
Surface Anchoring ◽  
Anchoring Energy
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