The influence of surface treatment on the in-plane smectic layer reorientation

Abstract

The dependence of the dynamic behaviour of the smectic C* layer reorientation on application of asymmetric electric fields is investigated for different surface treatment of the glass substrates, varying the alignment layer materials and rubbing conditions. It is found that already weak monostable anchoring limits the layer reorientation to twice the amount of the molecular tilt angle, while degenerate planar alignment promotes a continuous, unlimited rotation. Different layer reorientation times are observed for different alignment layer materials and can be correlated to the anchoring strength. Stronger anchoring hinders the reorientation of smectic layers. The number of buffing cycles (rubbing strength) does not have the expected pronounced effect on the layer reorientation, although increasing layer reorientation times are observed for increasing number of alignment layer rubbing cycles.

Key Words:

• Ferroelectric liquid crystals
• smectic layer reorientation
• alignment layer treatment