Pretilted Nematic Layers of 5CB on PTFE Treated Glass Supports

Abstract

Planar nematic layers of 5CB oriented by “sliding on” nanolayers of PTFE were studied by electrooptic methods. Deposited layers have been characterized by AFM and polarizing videomicroscopy. By using a drop method it was established that the preferred director alignment is tilted opposite to the sliding direction. In some of these samples an unusual modulated domain pattern after switching off a prolonged a.c. excitation was observed for the first time. A possible relation between the domain origin and loosely deposited PTFE layers was suggested.

Keywords:

• interfaces
• liquid crystals
• polytetrafluoro-ethylen coating
• pretilt angle

Acknowledgments

This study was performed in the framework of a CNR-BAS joint project. The authors are indebted to Maria DeSanto for AFM characterization.