Self-assembled azo-dye film as an efficient liquid crystal aligning layer

Abstract

This paper reports on the use of self-assembled monolayer films with azo-dye molecules for liquid crystal alignment. The film growth was monitored by absorption measurements and the thickness and morphology determined by atomic force microscopy. The dynamic photo-alignment data revealed that the orientation of the azo-groups is facilitated in the presence of the liquid crystal. These substrates induced strong anchoring of the E7 liquid crystal molecules, allowing their application in liquid crystal displays. The advantages of this system are the reversibility, where the active part of the device can be altered, and that any size or shape can easily be inscribed. Another important point is the absence of mechanical contact during the substrate preparation, making this process clean.

Keywords:

• layer-by-layer technique
• azo-dye
• liquid crystals

Acknowledgements

The authors thank the Brazilian Agencies CNPq (#564219/2008-8), FAPESC, INEO/MCT and Nanobiomed/CAPES for financial support of this research.