Peculiarities of mechanical and dielectric properties of a photoswitchable cybotatic-type nematic

Abstract

Recently the liquid crystal displays (LCDs) technology, the main consumer of liquid crystalline materials, is constantly looking for new compounds with special physical properties. The discovery of novel types of mesogenic material, the so-called banana-shaped liquid crystals or bent-core liquid crystals (BCLCs), opened new possibilities in the field of liquid crystals. These newly discovered BCLCs materials exhibit polar order and chiral superstructures in their mesophases, although the molecules themselves are not chiral. Since then, a vast number of BCLCs exhibiting a great variety of interesting liquid crystalline phases have been synthesised and investigated. The presence of azo groups in bent-core mesogens structures allow to use reversible trans-cis isomerisation upon photoirradiation. Initially, these materials were considered to be of no use in LCDs industry because of their photosensitive nature. But today, the same phenomenon is the basis of their new applications. The combination of photosensitivity and liquid crystalline properties in the same molecule allows the material to be exploited for different applications in photonics such as optical data storage, photochemical molecular switches, polarisation holography, sensors and nonlinear optics.