An effect of chiral dopants on mesomorphic and electro-optical properties of ferroelectric smectic mixture

Abstract

ABSTRACTThe aim of the presented research was an assessment of an effect of chiral dopants on the physical and electro-optical properties of a ferroelectric smectic mixture which is a key factor of elaboration of working ferroelectric liquid crystal (FLC) mixtures of tailored properties, especially with the tilt angle value near 22.5° in a broad temperature range. Testing FLC mixtures were prepared using the common pyrimidine-based parent mixture F4 doped with three different chiral dopants. The thermal characteristic of the optical tilt angle , tilt angle calculated by means of X-ray diffraction method , spontaneous polarisation and layer spacing of obtained FLC mixtures were studied. Based on the above measurements and computer calculations, the relationship between spontaneous polarisation and tilt angle was discussed. Electro-optical performance of the Surface Stabilised Ferroelectric Liquid Crystal (SSFLC) structures was observed. The relation between the molecular properties of chiral dopants and the electro-optical and physical properties of obtained FLC mixtures is considered in frames of the extended microscopic model of the spontaneous polarisation in FLCs.