Measuring the Anisotropy in Interfacial Tension of Nematic Liquid Crystals

Liquid crystal (LC) phases typically show anisotropic alignment-dependent properties, such as viscosity and dielectric permittivity, so it stands to reason that LCs also have interfacial tensions. Measuring the tension γ of an LC with conventional methods, pendant drops, can be challenging, however, especially when we need know for different aligning conditions, is case seek Δγ, anisotropy. Here, present measurements Δγ common synthetic nematic compound 5CB against water using a microfluidic droplet aspiration technique. To ensure tangential normal alignment, respectively, add poly(vinyl alcohol) (PVA) sodium dodecylsulfate (SDS), stabilizer measure concentrations stabilizer. By fitting Szyszkowski equation data, extrapolate zero-stabilizer concentration, obtaining pure each alignment. For find γ⊥=31.9±0.8 mN·m−1, on order 1 mN·m−1 greater than γ||=30.8±5 This resonates empirical knowledge aligns tangentially interface water. The main uncertainty arises from use polymeric PVA tangential-promoting Future improvements in accuracy may expected if replaced by low molar mass ensures