Controlling the orientation of the columns in a DLC by irradiation with IR

Polarized infrared photoinduced change of liquid crystal domains was investigated for a hexagonal columnar phase of a liquid crystalline triphenylene derivative. A uniform and anisotropic change of domains was observed when a polarized infrared light corresponding to the wavelength of the absorption band of triphenylene core was irradiated. IR absorption dichroism is induced as a result of the reorientation of triphenylene core. The texture observation and polarized microscopic FT-IR spectra show that a change of the molecular alignment occurred and the direction of columns depends on the polarization direction of an actinic infrared light. The technique could provide a novel technology to control the columnar alignment of supra-molecular systems.