Non-monotonous shear rate dependence of dielectric relaxation frequency of a nematic liquid crystal revealed by rheo-dielectric spectroscopy
arxiv(2024)
摘要
Dielectric relaxation of materials provides important information on the
polarisation dynamics at different time scales. We study the dielectric
relaxation of a nematic liquid crystal under steady rotational shear and
simultaneously measure the viscosity. The dielectric anisotropy of the nematic
is positive and the applied field is parallel to the velocity gradient
direction with a magnitude larger than the Freedericksz threshold field. The
complex dielectric constant as well as the effective viscosity decreases
rapidly with increasing shear rate. The dielectric relaxation frequency
exhibits a non-monotonous shear rate dependence, first decreasing but beyond a
critical shear rate increasing. Our experiments suggest the emergence of
collective dipolar relaxation under the influence of the competing effects of
hydrodynamic and dielectric torques.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要