Liquid crystal sol containing oleophilic Pd nanoparticles for liquid crystal device

We have succeeded in preparation of liquid crystal sol containing oleophilic Pd nanoparticles (NPs) stabilized by multidentate copolymer and fabrication of the twisted nematic liquid crystal devices (TN-LCDs) by using Pd NP-containing liquid crystal sol. Oleophilic Pd NPs were prepared by refluxing Pd acetate solution in toluene/ethanol containing poly(N-vinyl-2-pyroridone-co-styrene). Oleophilic Pd NPs showed better solubility in liquid crystal medium than poly(N-vinyl-2-pyrrolidone)-stabilized NPs. The TN-LCDs were fabricated by using two kinds of practical liquid crystal materials doped with oleophilic Pd NPs. The NP-doped LCD showed 22% faster response than non-doped one at -20 degrees C without a chiral dopant. However, LCDs fabricated by liquid crystal materials with a chiral dopant were not affected by NPs. These results suggest that the effect of NPs on the electro-optic performance of LCD is incompatible with that of a chiral dopant.