A slow damped oscillation of nematic disclination was observed after abrupt (step-wise) change of DC electric field. The oscillation was not observed under high frequency AC field. These results imply that molecular reorientation in-
fluence disclination dynamics after abrupt switching. An effective model, different from the elastic theory, was proposed to analyze the results.
(J. Phys. Soc. Jpn., 84, 033601 (2015))
This paper reports an experimental study of the dynamics of s = (+/-)1/2 disclinations in the nematic liquid crystalline (LC) phase of 4-cyano-4'-n-pentylbiphenyl (5CB) under strong anchoring condition. The backflow brings asymmetry in annihilation dynamics of disclinations. To reveal the surface effect on backflow, we observed the motion of disclination pair for a various cell gap d. Although the velocity ratio of s = (+/-)1/2 disclinations is comparable with a theoretical prediction, it decreased around the cell gap d = 1micro m when velocity ratio was reduced. This observation shows that the backflow is suppressed in the LC cell with d = 1 micro m. The anchoring effect is analyzed through a model calculation within an elastic theory.
(J. Phys. Soc. Jpn., 81, 074603 (2012))
In this paper, we report an experimental study of the dynamics of s =1/2 disclinations in the nematic liquid-crystalline phase of 4-cyano-4'-n-pentylbiphenyl (5CB) under a strong anchoring condition in an electric field. Their motion is clearly asymmetric; the +1/2 disclination moves almost twice as fast as the (+/-)1/2 one even under a strong anchoring condition, which is very similar to the case without the anchoring effect. An electric field significantly affects the rotation of the director around the disclinations, but only slightly affects backflow.
(J. Phys. Soc. Jpn., 81, 034601 (2012))
Return to Kazuya's Home Page