Quartic coupling and its effect on wetting behaviors in nematic liquid crystals.

Based on the fact that rubbed groove patterns also affect the anchoring of liquid crystals at substrates, a quartic coupling is included in constructing the surface energy for a liquid crystal cell. The phase diagram and the wetting behaviors of the liquid crystal cell, bounded by surfactant-laden interfaces in a magnetic field perpendicular to the substrate are discussed by taking the quartic coupling into account. The nematic order increases at the surface while it decreases in the bulk as a result of the introduction of quartic substrate–liquid crystal coupling, indicating that the groove anchoring makes the liquid crystal molecules align more orderly near the substrate than away from it. This causes a different wetting behavior: complete wetting. [ABSTRACT FROM AUTHOR]