Optical storage effect due to photopolymerization of mesogenic twin molecules

The photopolymerization of diacrylate mixtures containing a nematic twin co mpound and a chiral dopant leads to perfectly stable, highly crosslinked ch olesteric networks. The Bragg reflection spectra of the respective monomer and polymer mixtures were measured and the influences of the chemical struc ture, the temperature and the concentration of chiral dopant on the reflect ion wavelength was studied. Subsequent UV exposures of different parts of t he sample at different temperatures are suitable to generate colored patter ns. Deposition of several cholesteric films with different Bragg wavelength s results in additive color mixing. (C) 2000 American Institute of Physics. [S0021-8979(00)06605-6].