Voltage-assisted ion reduction in liquid crystal-silica nanoparticle dispersions

We demonstrate an effective method of reducing mobile ions in a silica nanoparticle (SN)-doped liquid crystal (LC) cell by alternating-current high-voltage pulse treatment (ACHVPT). In this method, the director distortion in LCs near the substrate creates a lifting force that moves the SNs toward the substrate. The moving SNs trap mobile ions in the cell bulk. After ACHVPT, the SNs and mobile ions are adsorbed onto the substrates, thereby significantly decreasing cell ion density. The ion density of the SN-doped LC cell after ACHVPT treatment is 1.5% of that of a pristine LC cell. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4760277]