Electrically induced and thermally erased properties of side‐chain liquid crystalline polymer/liquid crystal/chiral dopant composites

Abstract

The properties of synthesized side‐chain liquid crystalline polymer (SCLCP)/liquid crystal (LC)/chiral dopant composites having a chiral nematic (N*) phase at room temperature were investigated by polarized optical microscopy (POM) and a UV/VIS/NIR spectrophotometer. The composite exhibited a planar texture after it was filled into cells under homogeneous boundary conditions and it was transparent. When an electric field was applied to the composite, a focal conic texture was formed and the composite became light scattering. After the electric field was turned off, the light‐scattering state remained stable for some time, i.e. the light‐scattering state exhibited a memory effect. The focal conic texture changed into the planar texture when the composite was heated and the composite became transparent again. Therefore, the composite had electrically induced and thermally erased properties. The SCLCP had some influence on the memory effect and on the thermo‐electro‐optical properties of the composite.

Acknowledgements

The authors are grateful to 2004 Key Fund of Chinese Ministry of Education (Grant No. 104187), Doctorate Fund of Chinese Universities (Grant No. 20050008036) and Fund of Scientific Plan of Beijing City (Grant No.Y0405004040121) for financial support.