Effects on thermo‐optical properties of the composition of a polymer‐stabilised liquid crystal with a smectic A–chiral nematic phase transition

Abstract

A photopolymerisable monomer/liquid crystal (LC)/chiral dopant/photoinitiator mixture with a smectic A (SmA*)–chiral nematic (N*) phase transition was prepared. After the SmA* phase was homeotropically oriented and then irradiated by ultraviolet light, a homeotropically oriented polymer network was formed in the SmA* phase and then a homeotropically oriented polymer network‐stabilised liquid crystal (PSLC) film with a SmA*–N* phase transition was prepared. In the temperature range of the SmA* phase, the LC molecules were homeotropically oriented and the film exhibited a transparent state. However, in the temperature range of the N* phase, the film exhibited a strong light‐scattering state owing to the fact that the LC molecules adopted a focal conic alignment affected by the homeotropically oriented polymer network. The strong light‐scattering state of the N* phase could be changed into a transparent one when an electric field was applied. The focus of this study was on the effects of composition of the PSLC film on its thermo‐optical and electro‐optical properties.

Keywords:

• PSLC
• smectic A–chiral nematic transition
• thermo‐optical properties
• electro‐optical properties

Acknowledgements

Financial support from Hi‐tech Research and Development Program of China (Grant No. 2006AA03Z108) and Projects of Chinese National Science and Technology Tackling Key Problems (Grant No. 2006BAI03A09) are gratefully acknowledged.