Influence of Magnetic and D. C. Electric Fields on the Molecular Alignment of a Nematic Liquid Crystal

1974 ◽  
Vol 29 (1) ◽  
pp. 155-163 ◽  
Author(s):  
T. E. Kubaska ◽  
C. E. Tarr ◽  
T. B. Tripp
Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1029
Author(s):  
Dina V. Shmeliova ◽  
Sergey V. Pasechnik ◽  
Semen S. Kharlamov ◽  
Alexandre V. Zakharov ◽  
Eugeny P. Pozhidaev ◽  
...  

In this paper we report the new experimental results on the rise of a liquid crystal in flat capillaries with inner photosensitive surfaces. The capillaries with different surface orientations were prepared by the use of the photo-alignment technique. Such a surface treatment makes it possible to eliminate the noncontrollable influence of a nanorelief on the wetting process, which takes place in the rubbing treatment technique previously used in similar experiments. The dynamics of the capillary rise of a nematic liquid crystal 5CB (4-cyano-4′-pentylbiphenyl) in vertical plane capillaries with photo-aligned substrates were studied for the first time. It was found that the stationary value of a contact angle weakly depends on the direction of a planar surface orientation relative to the direction of a capillary rise. It has been shown that the application of strong electric fields resulted in a decreasing of the contact angle. The results, obtained for the nematic liquid crystal, are compared with the results of an investigation of the capillary flow in a shock-free ferroelectric smectic phase.


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1929 ◽  
Author(s):  
Shuan-Yu Huang ◽  
Bing-Yau Huang ◽  
Chi-Chung Kang ◽  
Chie-Tong Kuo

This work demonstrates an electrically-tunable nematic liquid crystal (NLC) diffraction grating with a periodic electrode structure, and discusses the polarization properties of its diffraction. The efficiency of the first-order diffraction can be gradually controlled by applying external electric fields cross the NLC, and the maximum diffraction efficiency of the first-order diffraction that can be obtained is around 12.5% under the applied voltage of 5.0 V. In addition to the applied electric field, the efficiency of the first-order diffraction can also vary by changing the polarized state of the incident beam. Antisymmetric polarization states with symmetrical intensities in the diffractions corresponding to the +1 and −1 order diffraction signals are also demonstrated.


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