Electro-optic modulation by silica-nanostructured nematic system (aerosil/7CB nanocomposite)

We report an experimental study on the electro-optic (EO) response of thin (25 μm) films of a gel nanocomposite produced from heptylcyanobiphenyl (7CB) nematic liquid crystal and 3 wt.% hydrophilic aerosil nanoparticles (ANPs) of size ca. 7 nm. Under alternating-current (AC) electric field such films of nanostructured LC exhibit a gradual increase of light transmittance with the increasing voltage, a reversible EO behavior of transmitted light, as well as a specific effect of slightly varying amplitude-frequency EO modulation at the doubled frequency of the driving electric field. The slope of the EO modulation characteristics of ANPs/7CB can be controlled by the field. These features make the studied nematic nanocomposites attractive for EO modulation applications.