Ordering and self-diffusion in the first molecular layer at a liquid-crystal–polymer interface

Abstract

${}_{}{}^2{}_{}{}^{}\mathrm{H}$ NMR of a liquid crystal confined to submicron cylindrical cavities, in a 17 K interval above the nematic-isotropic transition, reveals a weakly orientationally ordered molecular layer at the cavity wall governed by local interactions. The order (${\mathit{S}}_0$=0.02) is temperature independent so that a partial wetting is realized with no prewetting transition expected. A molecular exchange rate between the surface layer and the bulk is measured to be ∼${10}^3$ ${\mathrm{s}}^{\mathrm{-}1}$. The coherence length measuring the order penetrating further into the cavity is described by α=0.4 and ${\xi }_0$=0.6 nm.