Wu Po-Chang, Lisetski Longin N, Lee Wei
Opt Express. 2015 May 4;23(9):11195-204. doi: 10.1364/OE.23.011195.
We focus on investigating the dielectric behaviors and the low-frequency texture transitions in a cholesteric liquid crystal (CLC) doped with graphene nanoplatelets (GNPs) by means of dielectric spectroscopy and measurements of electro-optical responses. The experimental results indicate that incorporating GNPs at a content of 0.5 wt% into the CLC leads to significant suppression of ionic behaviors, as manifested by the reduction in ionic density, diffusivity, and relaxation frequency. In addition, the electro-optical properties of the GNP-doped CLC cell show the lowered operation voltage for the switching from the planar to focal conic state and the absence of the low-frequency focal-conic-to-uniform-lying-helix texture transition. Such results are attributable to the effects of GNPs as nuclei in the CLC medium, giving rise to the repression of the ionic and electrohydrodynamic effects.
我们通过介电谱和电光响应测量，专注于研究掺杂有石墨烯纳米片（GNP）的胆甾相液晶（CLC）中的介电行为和低频织构转变。实验结果表明，将含量为0.5 wt%的GNP掺入CLC中会导致离子行为受到显著抑制，这表现为离子密度、扩散率和弛豫频率的降低。此外，掺杂GNP的CLC盒的电光特性显示，从平面态切换到焦锥态的操作电压降低，并且不存在低频焦锥态到均匀平躺螺旋织构的转变。这些结果归因于GNP作为CLC介质中核的作用，从而抑制了离子和电流体动力学效应。
