Dynamics of a ferroelectric liquid crystal with a naphthalene ring during electric-field-induced switching studied by time-resolved infrared spectroscopy combined with two-dimensional correlation spectroscopy.
The dynamics of a ferroelectric liquid crystal with a naphthalene ring (FLC-3) during the electric-field-induced switching between two surface-stabilized ferroelectric liquid crystal states were investigated by time-resolved infrared (IR) spectroscopy combined with two-dimensional (2D) correlation spectroscopy. Time-resolved IR spectra of FLC-3 in a planar-aligned cell were measured as a function of the polarization angle range from 0 degree to 180 degrees under a rectangular electric field of +/- 40 V with a 5 kHz frequency in the smectic-C* (Sm-C*) phase at 137 degrees C. From these spectra we explore details about the reorientation process of the alkyl chains, the core, and the large C=O dipole moments of FLC-3 at all the delay times. The 2D correlation spectroscopy was applied to the polarization-angle-dependent spectra for different delay times and to the time-resolved spectra at certain polarization angles to reveal the relative orientation of the C=O groups and the core moiety during the electric-field-induced switching. It was found from the present study that the relative orientation of the C=O groups and the core remains unchanged during the initial period of the reorientation, while it is reversed at a certain moment and then kept unchanged again. Moreover, the alkyl chains, C=O groups, and core moieties posses different dynamics during the fast course of electric-field-induced switching by analyzing time-resolved spectra.
Zhao
Jinggang
J
Department of Chemistry, School of Science, Kwansei-Gakuin University, 2-1, Gakuen Sanda, Hyogo 669-1337, Japan.
Jiang
Jianhui
J
Yoshihara
Toshiaki
T
Siesler
Heinz W
HW
Ozaki
Yukihiro
Y
D003460:Crystallization / Q000295:instrumentation / Q000379:methods; D003461:Crystallography / Q000379:methods*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods*; D004574:Electromagnetic Fields; D005296:Ferrous Compounds; D050866:Liquid Crystals; D008280:Magnetics; D059346:Magnets; D008968:Molecular Conformation; D009281:Naphthalenes / Q000737:chemistry* / Q000528:radiation effects*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013057:Spectrum Analysis / Q000379:methods; D013223:Statistics as Topic
D005296:Ferrous Compounds; D009281:Naphthalenes; D012996:Solutions; C481874:naphthlene ring ferromagnetic liquid crystal; C031721:naphthalene