Photopolarimetric investigations of the anchoring energy strength for a nematic liquid crystal on polyaniline boundary surfaces

We report a photopolarimetric study concerning with the influence of the boundary surfaces and the surface charge buildup on the anchoring energy in nematic liquid crystalline electo-optical cells. By employing a field-on approach combined with a high precision photopolarimetric polarization method we simultaneously measure the Stokes parameters of the transmitted light. By using a standard Saturation Voltage Method (SVM) we implicitly determine the anchoring energy values for two different sets of samples, having soft and hard rubbing boundary constraints. The polyaniline coated substrates play a key role in weakening the anchoring energy during a bias-controlled injection process and allows obtaining important physical information on the investigated systems.