Kinetic Processes Of χ Disclination In Cholesteric Phases Using A Landau-de Gennes Theory

In this paper,we select a cholesteric liquid crystal film with two stable degenerate configurations as the research model which is based on Landau-de Gennes kinetic theory,and then carry on numerical calculation.We have investigated the kinetic processes ofχdisclination in the model.There are two parts in this paper:1.We investigate the effect of chirality and the evolution time on the disclination in cholesteric liquid crystal film without external electric field.The center of disclination will move to the right when chirality gets bigger or the evolution time takes longer.2.We investigate the effect of external electric field on the disclination in cholesteric liquid crystal film with certain chirality.（1）Under the conditions of same evolution time and E<30V/μm,the location of disclination ramains the same,and defect area is biaxial,and the angle between director and x-y plane becomes bigger with electric field intensity increasing.The center of disclination moves down,and defect area expands meanwhile the center becomes into uniaxial state when we continue to enhance the electric field intensity.The component of director along z axis closes to maximum.The director parallels with z axis when electric field intensity increases to a certain value.At the same time,χdisclination splits intoτ^-1/2λ⁺1/21/2 pairs.χdisclination finally disappears when E>43V/μm and so the film is uniaxial state.（2）Under the conditions of E=35V/μm and different evolution time,the center of disclination moves down with evolution time taking long.The angle between the director of disclination’s center and x-y plane alone x=dx/2 becomes bigger.χdisclination splits intoτ^-1/2λ⁺1/21/2 pairs when the evolution time achieves to a certain amount of time.