  The creation of aligning layers for the uniform orientation of liquid
crystals is significant for both research and the application of liquid
crystals. For all applications, the creation of aligning layers possessing
controllable characteristics such as azimuthal and polar anchoring energies,
easy-axis of director alignment and pre-tilt angle, in the same way as it is
achieved by using photoaligning layers processed by light, is very important.
Here, aligning properties of hybrid aligning layers created on the basis of
sapphire surfaces additionally coated by photoaligning layer of PVCN-F are
studied. These hybrid layers possess the properties of the nano-structured
sapphire layer and the photosensitive PVCN-F layer, and complement each other.
The irradiation time dependence of the azimuthal anchoring energy of the hybrid
layers is studied. By using certain experimental conditions during irradiation
of hybrid layers, e.g., polarisation of light and irradiation time, a minimum
value of the azimuthal anchoring energy, close to zero, was obtained. Atomic
force microscope studies of the irradiated hybrid layers were also carried out.
It was found that the behavior of the contact angle of nematic droplets placed
on treated sapphire surfaces are in good agreement with properties of hybrid
aligning layers and parameters of structuring surface obtained from AFM images.
