Аннотация:Multifunctional cholesteric liquid crystalline (LC) polymer-stabilised composite with photo- andelectro-controllable photonic band gap was prepared and its fast photo- and electro-opticalswitching was demonstrated. The composite was prepared by a template method implying thepolymerisation of cholesteric mixture consisting of several components, such as nematic liquidcrystal compounds, chiral dopant, polymerisable mono- and diacrylates as well as photoinitiator.UV-induced polymerisation and subsequent removing of the low-molar-mass components enablesto obtain porous cholesteric polymer matrix, which was used for filling with photochromic nematicmixture. Application of electric field or UV-irradiation shifts the photonic band gap to the short-wavelength spectral range. In the case of an electric field, this shift is associated with alignment ofLC molecules along the electric field and deformation of the cholesteric helical structure. UV lightaction induces E-Z isomerisation of the azobenzene-containing molecules of photochromic mix-ture and decrease in their molecular anisometry leading to decrease in birefringence. Both electro-and photo-induced changes are completely reversible and switching the electric field off and/orirradiation with visible light completely recovers initial shape of selective reflection band. Theswitching is very fast and takes several seconds for the light action and less than one second for theelectric field.
