Fig. 3.

Extrapolation of film tension to zero thickness yields surface tension. (A) Film tension in the region in contact with liquid as a function of film thickness. We find that all three cases exhibit a nonzero intercept, which we interpret as the surface tension. (Inset) There is a systematic difference on the same sample depending on the type of liquid in contact with the film. The data plotted here therefore represent the difference in film tension simply due to a change of the liquid in contact with the solid. (B) Film tension in the region immediately outside the contact line as a function of film thickness.