Glassforming liquid crystalline equimolar mixtures of MHPOBC and fluorinated compounds -- structural, optical, and dielectric properties
arXiv:2501.16980 · doi:10.1016/j.molliq.2025.127939
Abstract
Three liquid crystalline equimolar mixtures are formulated, each containing the MHPOBC compound and the homolog from the 3FmHPhF6 series with m = 4, 5, and 6. The properties of the mixtures are investigated by differential scanning calorimetry, polarizing optical microscopy, X-ray diffraction, electro-optic measurements, and UV-Vis-NIR and dielectric spectroscopies. In all mixtures, the smectic A*, smectic C*, and smectic C* phases are observed. Each mixture can be supercooled and forms the glass of smectic C* at 225-238 K. The glass transition temperature decreases with the increasing CH chain length in the 3FmHPhF6 molecule. The tilt angle in the smectic C* phase reaches 36.5-37.5°. The selective reflection of light in the visible and near-infrared spectral ranges is observed, with a strong dependence of the reflected light's wavenumber on temperature.
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