2C05 Polarized microscopic FT-IR spectroscopic study on molecular orientation change in chiral nematic liquid crystal exhibiting blue phase by phase transition

Abstract

Study on molecular orientation changes by phase transition is important to reveal the stability mechanism of chiral nematic liquid crystal (N^*LC) exhibiting blue phases (BPs) and developing of new generation LC devices as well. In this study, the polarized microscopic FT-IR spectroscopy has been applied for study on molecular orientation of N^*LC by the phase transition. The vertical and in-plane molecular orientation change of NLC molecules have been determined by band intensity ratio CN/CH_2 of non-polarized IR spectra and band intensity of CN stretching mode of polarized IR spectra, respectively. In conclusion, the lattice of BP I is more likely to affect the molecular orientation change of N^*LC on cooling process.