The switching process in a ferroelectric liquid crystalline side-chain polymer by time-resolved step-scan FT-IR spectroscopy and 2D correlation analysis

Time-resolved Fourier-transform infrared (FT-IR) spectroscopy and two-dimensional (2D) correlation analysis were used to study the segmental mobility of a ferroelectric liquid-crystalline polymer (FLCP) in the S-c* phase. It has been shown that, under the influence of an electric field, only the mesogen reorients together with the terminal group attached to it and a fragment of the spacer. The remaining part of the spacer and the main chain of the FLCP do not participate in the reorientation. The estimated relaxation times for selected bands revealed that, according to the theoretical predictions, the reorientation rate increases with temperature. This effect is due to the decrease of the reorientational viscosity with temperature. However, the temperature does not effect the mechanism of the reorientation on a molecular level. Although the experiment was performed at different voltages we did not observe a field-dependence of the relaxation times. (C) 1998 Elsevier Science B.V. All rights reserved.