PD01 Discontinuous helical pitch of cholesteric liquid crystals by photoisomerization of chiral azobenzene molecule.

Abstract

This paper describes discontinuous helical pitch of a cholesteric liquid crystal (ChLC) by photoisomerization of chiral azobenzene molecule with respect to an effect on its switching behavior. A mixture of E44, R811 and Azo (Figure 1) was prepared in weight of 68, 28 and 4 %. The mixture was injected in homogeneous glass cell with 2 and 5 mm cell gap. A selective reflection was observed at 800 nm, because of the planar structure in the glass cell. The wavelength of the ChLC was found to be shifted wavelength discontinuously. A magnitude of discontinuous change in the wavelength is related to the helical half pitch and number of the helical pitch in the glass cell.