Thermal stabilization of the smectic-Cα* phase by doping with photo-active reactive mesogen

Abstract

• The incorporation of monomers into liquid crystals changes their physical properties. • Dielectric properties and switching behaviour of liquid crystal molecules depend on the monomer concentration. • A new method for thermal stabilization of the smectic-Ca* phase is presented. • The admixture of monomer causes a relatively small decrease in spontaneous polarization of the liquid crystal system. The effect of a photo-active reactive mesogen 4-(3-acryloyloxypropyloxy)-benzoesure2-methyl-1,4-phenylester on an antiferroelectric liquid crystal was investigated in the context of possible broadening of the temperature range in which the smectic-C α * phase exists in newly synthesized hybrid materials promising for optical applications. In the mixtures of various reactive mesogen concentrations from 1 to 9 wt. %, dielectric spectroscopy and reversal current method were used to determine the temperature range and switching time of the smectic-C α * phase. As a result of reactive mesogen doping, the thermal stabilization of the smectic-C α * phase over 21.5 °C, around a room temperature, i.e. between 26.5 and 48 °C, was confirmed in the modified liquid crystal system.