Molecular Crystals and Liquid Crystals, Vol.647, No.1, 385-394, 2017
Impact of dye on the switching responses of polymer dispersed ferroelectric liquid crystal
Polymer dispersed ferroelectric liquid crystals (PDFLCs) have disclosed an enormous approach for use in electro-optic and display technology since ferroelectric liquid crystals (FLCs) have inherently fast switching speeds. In this work, we equipped dichroic PDFLC using dye-doped chiral SmC* liquid crystal (LC) and ultra-violet (UV) curable polymer by polymerization induced phase separation (PIPS) method. All fundamental material aspects like optical transmissions, spontaneous polarization, threshold voltage, contrast ratio and response time as a function of applied voltage, temperature, and dye concentration were examined. In the electro-optic study, 82% transmission with a threshold field value approximate to 0.6 V/m was observed for PDFLC, however, 90% transmission was achieved with a threshold field approximate to 0.3 V/m at the dye concentration of 0.125% (wt./wt.). As a result, present dichroic PDFLC device shows microseconds switching response, higher polarization value and superior contrast, at low dye concentration.
Keywords:Ferroelectric liquid crystal;dichroic polymer dispersed ferroelectric liquid crystal;polymerization induced phase separation;droplet morphology;anthraquinone dye