Order Reconstruction in a Nanoconfined Nematic Liquid Crystal between Two Coaxial Cylinders

Materials

Xuan Zhou²  Zhidong Zhang¹  Qian Zhang²  Wenjiang Ye² 

[1] Department of Physics, Hebei University of Technology, Tianjin 300401, China

关键词: liquid crystal;    order reconstruction;    disclination loop;    cylindrical wall;    biaxial transition;    Landau–de Gennes theory;   

DOI  :  10.3390/ma8125446

来源: mdpi

【 摘 要 】

The dynamics of a disclination loop (s = ±1/2) in nematic liquid crystals constrained between two coaxial cylinders were investigated based on two-dimensional Landau–de Gennes tensorial formalism by using a finite-difference iterative method. The effect of thickness (d = R₂ − R₁, where R₁ and R₂ represent the internal and external radii of the cylindrical cavity, respectively) on the director distribution of the defect was simulated using different R₁ values. The results show that the order reconstruction occurs at a critical value of d_c, which decreases with increasing inner ratio R₁. The loop also shrinks, and the defect center deviates from the middle of the system, which is a non-planar structure. The deviation decreases with decreasing d or increasing R₁, implying that the system tends to be a planar cell. Two models were then established to analyze the combined effect of non-planar geometry and electric field. The common action of these parameters facilitates order reconstruction, whereas their opposite action complicates the process.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.