Effect of the magnetic nanoparticle concentration on the electro-optical properties of the polymer-dispersed liquid crystals
Xiangshen Meng, Jian Li, Yueqiang Lin, Xiaodong Liu, Jianwei Zhao, Guoqing Li, Decai Li, Zhenghong He
Abstract
In this paper, we investigated the electro-optical properties of the dilute magnetic polymer dispersed liquid crystals (PDLCs) prepared with the liquid crystal colloids containing low concentrations of γ-Fe2O3 nanoparticles. The doped nanoparticles have hardly changed the morphology of PDLCs, but they have significantly changed the threshold voltage, saturation voltage, and contrast ratio of PDLCs. Such changes result from ionic adsorption in competition with the concentration of the nanoparticles. When the concentration of the nanoparticles was below the critical concentration, the adsorption of free ions was dominant, and the contrast ratio increased while the saturation voltage decreased. However, when the concentration of the nanoparticles was above the critical concentration, the intrinsic electro-optical effect of the nanoparticles was dominant, and the contrast ratio decreased while the saturation voltage increased.