Photoresponsive azo-doped aerosil/7CB nematic liquid-crystalline nanocomposite films: the role of polyimide alignment layers of the films

We studied thin films (25 µm-thick) of nanomaterials composed from 3 wt.% aerosil nanospheres and the room-temperature nematic liquid crystal 4-n-heptyl cyanobiphenyl (7CB). The inclusion of 3 wt.% of the photoactive liquid crystal 4-(4'-ethoxyphenylazo)phenyl hexanoate (EPH) in the aerosil/7CB nanostructured nematics make them photoresponsive. The films had alignment layers from rubbed polyimide (PI). Our study is concentrated on the inspection of the PI-role for the photo-stimulated electro-optical properties of the considered EPH-doped aerosil/7CB nanocomposite films.