Effects of polyhedral oligomeric silsesquioxane and silicon microstructure on the electric-optical performance of polymer dispersed liquid crystals

In this work, two silicon nanomaterials are doped into polymer/liquid crystal composites by a facile method. SEM and FT-IR characterizations indicate that SiO 2 -SH and synthesized thiol polyhedral oligomeric silsesquioxane (POSS-SH) have been successfully implanted into PDLCs successfully. The electro-optical tests imply that the electro-optical performance of PDLC films can be greatly enhanced by doping proper amounts of SiO 2 -SH nanoparticles and nanostructured POSS-SH into the polymer matrix . The driving voltage can be reduced by nearly 78.2% if the concentration of SiO 2 -SH is 4 wt%; whereas only nearly 60% driving voltage is reduced when 4 wt% POSS-SH is doped into system, indicating better electric-optical performance regulation effect of SiO 2 . The lower driving voltage of SiO 2 -SH doped PDLC samples may be due to the existence of high content –SH on the surface of nanoparticles , which can conduct click reactions with acrylate bond under the effect of initiator.