Photoaligning materials photoalignment layers

V. Strehmel, B. Stiller, B. Strehmel, A. M. Sarker, and D. C. Neckers, Fluorinated Distyrylbenzenes Containing Copolymers for Photoinduced Formation of Anisotropic Materials as Photoalignment Layers for Liquid Crystals. In Photoinitiated Polymerization, Vol. 847, K. D. Belfield and J. V. Crivello, Eds., American Chemical Society, Washington, DC, 2003, p. 482. 

A. Contoret, S. Farrar, P. Jackson, S. Khan, L. May, M. O Neill, J. NichoUs, S. Kelly, and G. Richards, Polarized electroluminescence from an anisotropic nematic network on a non-contact photoalignment layer. Advanced Materials 12, 971 (2000). 

Molecular design and synthesis have been used to improve significantly the performance of photoalignment layers. Photochemically and thermally stable materials are now available, which show strong LC anchoring and require low exposure threshold intensities to achieve LC alignment. 

As follows from Table 3.1, pure reorientation (diffusion) is the most suitable mechanism for LC photoalignment. The commercialization of the materials produced by the Die Corporation (Japan) is expected soon [45, 46]. The first target should be the photoaligning of monomers and LC polymers for phase retarder applications (Chapter 5). Photoaligning with azo-dye layers will be considered below. 

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