Temperature dependence of azimuthal anchoring strength of liquid crystals on microgrooved glass substrate

Abstract

The temperature dependence of the azimuthal anchoring strength of the nematic liquid crystal (LC) 4'-n-pentyl-4cyanobiphenyl (5CB) on parallel grooved glass substrates has been studied. The U-shaped grooves are prepared by reactive ion etching. Two parallel grooved substrates with chiral doped 5CB sandwiched in between are used to form an LC cell. The azimuthal anchoring strength in the nematic temperature range is determined by measuring the twist angle in the LC cells using an optical method at two laser wavelengths. The anchoring strength decreases steadily with increasing temperature. The change in the anchoring strength is attributed to-the change in the elastic constant K(22) unless the temperature is close to the clearing point.