Figure 9.

Experimental set-ups and angle diagrams used to determine azimuthal (A and B) and zenithal (C and D) anchoring energies. (A) Schematic illustration of a twisted nematic LC (TNLC). (B) Diagram depicting the angles used to characterize the TNLC between two polarizers. The azimuthal orientation of the easy axis of the LC (defined by φ ₃) and the azimuthal orientation of the LC director (defined by φ) are shown for both the top and bottom surfaces. Modified and reproduced with permission.¹⁴ (C–D) Schematic illustrations and corresponding definitions of angular displacements of the director in a LC film with planar-homeotropic hybrid anchoring conditions. The bottom surface is assumed to cause strong homeotropic anchoring and is used as a reference surface. The orientation of the easy axis of the LC at the top surface is characterized by the zenithal angle θ₃, and the orientation of the LC director is characterized by θ.