Abstract
Two groups of polymer dispersed liquid crystal films have been studied, one with a fixed cell thickness but varying liquid crystal (LC) concentrations and the other with a fixed LC concentration but varying cell thicknesses. A sudden decrease in transmittance with increasing temperature was observed for films whose LC domain sizes were comparable to their cell thicknesses. In particular, spontaneous alignment of LC directors was observed below ∼20°C when LC domains were formed spanning the space between upper and lower indium tin oxide‐coated glass substrates. With increasing temperature, this axially aligned homeotropic configuration changed gradually into homogeneous configurations. We believe that the sudden decrease in transmittance originated from the anchoring transition at the glass substrates and polymer walls. In addition, it has been found that the intensity of ultra violet irradiation has a strong effect on the director configuration of LC domains, and that the cure temperature affects the anchoring transition temperature significantly.
Acknowledgements
This research was supported in part by Daegu University Research Grant 2003.