ABSTRACT
Phase transition dynamics of liquid crystal (LC) was measured by the heterodyne transient grating (HD-TG) method to clarify the difference between the photochemical and photothermal phase transitions. The phase transition was induced by the photo-excitation of different guest dyes doped in the host liquid crystals; azobenzene and solvent red were used as photochemical and photothermal dyes as guest dyes. The photochemical phase transition was partly induced even at much lower temperature than the nematic – isotropic phase transition temperature (TNI) and the region was gradually increased as the temperature, while photothermal phase transition was induced in the whole area just when reaching TNI. Furthermore, the anisotropic re-alignment of molecules was observed in the phase recovery process.
Funding
This research work was supported by the Institute of Science and Engineering, Chuo University.