Low driving-voltage four-armed pentaerythritol and coumarin based compounds as potential materials for LCDs

The electro-optical properties of some four-armed liquid crystalline materials with pentaerytrithol core based on coumarin as mesogenic moiety is investigated. The mesogenic moiety is connected to the core via spacers with various chain lengths differing. The compounds are investigated via differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) equiped with a temperature controlled hot-stage. Field-Emission Scanning Electron Microscope (FESEM) and “High-Resolution Transmission Electron Microscope (HRTEM) measurements are exhibited a relatively spherical morphology with particle sizes of 145–174 nm. The electro-optical performance of the materials as thin films coated on indium-tin-oxide (ITO) glass substrates are investigated via applied voltage versus transmittance plots, exhibiting relatively low driving voltage values as low as 2.5–3 V. The ordinary (no) and extraordinary (ne) refractive indexes of the compounds at different temperatures are measured showing a good correspondence with the POM results. In conclusion, the studied materials have exhibited proper physicochemical and electro-optical properties as materials for liquid crystal displays (LCD). [Display omitted] •Electro-optical properties of pentaerytrithol-coumarin based liquid crystals studied.•Mesogenic moieties connected to core via spacers with various chain lengths.•DSC and temperature dependent no and ne of compounds corrlated with POM results.•Materials exhibited relatively low driving voltages as low as 2.5 and 3 V.