Line tension effects near first-order wetting transitions

The behavior of the line tension for n-octane or 1-octene droplets on a hex adecyltrichlorosilane coated Si wafer, near a first-order wetting transitio n, qualitatively agrees with the theoretical predictions of Indekeu [Physic a (Amsterdam) 183A, 439 (1992)] and the calculations of a number of other g roups. A simple phenomenological model possessing a repulsive barrier at l( o) = (5.1 +/- 0.2) nm and a horizontal correlation length xi = (0.40 +/- 0. 03) mu m provides a quantitative description of the experiments.