Photo-induced liquid crystal alignment on polyimide containing fluorine group

The photo-induced alignment properties of liquid crystals (LCs) on the polyimide films containing fluorine group were investigated. Pretilt angles increased with UV exposure time, but azimuthal anchoring energies and order parameters initially increased with UV exposure time and showed maximum values at a certain UV exposure time. The optical retardations of polyimide films suggest that the LC ordering depends on the pretilt angle of the LC cell.