Orientation of 5CB Molecules on Aligning Substrates Studied by Angle Resolved X-ray Photoelectron Spectroscopy

ABSTRACT

We studied alignment of 5CB molecules on several surfaces by Angle Resolved X-ray Photoelectron Spectroscopy. It was found that different surfaces orient 5CB molecules with different tilt while providing qualitatively the same type of the LC alignment in the bulk. In particular, quartz and PVA gave high tilt, while NaCl and glass gave very low tilt. At the same time all these surfaces provide degenerated quasi-planar alignment in LC bulk. These results point that the orientation of LC molecules in the bulk can strongly differ from the orientation of the first adsorbed monolayer and it is determined by integral anisotropic action of the surface and interface over interface region.

Keywords:

• alignment
• anchoring
• liquid crystal
• tilt
• XPS

Acknowledgments

We pleased to S. Shiyanovskii for valued discussions. The publication was made possible in part by CRDF grant UK-P1-2598-KV-04 “Insight the physical phenomena behind the light-induced anchoring”.