Immiscible blend of cholesteric copolymers as a new type of material with photoregulated optical properties

A blend containing two immiscible cholesteric comb-shaped polyacrylates was prepared. Upon light irradiation, one of the components is able to change the pitch of the cholesteric helix due to the isomerization of chiral photochromic side groups. The phase behavior and optical properties of the above blend were studied. Planarly oriented films based on the above blend show the two well-pronounced peaks of selective light reflection: one peak is seen in the visible spectral region whereas the other peak is observed in the near-IR region. Under the action of light, the long-wavelength peak is shifted to higher wavelengths whereas the second peak remains almost unchanged. The specific features of the kinetics of the photooptical processes taking place in this system were studied. The above immiscible blend is shown to be a new unique material for optical data recording and storage.