| Abstract
| - A general model for the Wilhelmy (fiber) surface tension measurement method for uniaxial nematicliquid crystals has been derived using fundamental principles and classical liquid-crystal physics. A rigorousformulation of the contributions of surface and bulk nematic elasticity was implemented for the Wilhelmymethod. The surface contribution is a function of the surface anchoring strength of the liquid-crystal freesurface and the director surface orientation at the solid−nematic−vapor common line. The exact bulkelasticity contribution is a function of the director field in the meniscus, which is a function of the nematic−fiber interactions, the size of the fiber, and the temperature, among other things. The specific form of theWihelmy model equation for four typical nematic textures was developed and analyzed. It is found thatthe effect may depend on the size of the fiber, the presence of disclinations, and the representative Frankelastic constants. The expression representing the actual measurement or apparent surface tension wasderived and used to identify the exact nature of the nematic contributions for typical nematic textures.Identification of material systems, experimental conditions, and geometric factors that enhance the impactof nematic ordering on the Wilhelmy surface tension measurements was given. A qualitative comparisonof the model prediction with experimental data highlights the utility of the derived equations.
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