Fluctuation effects on wetting films

We provide a quantitative experimental determination of the fluctuation rep ulsion that stabilizes wetting lms in systems for which the interfacial ten sion of one of the two interfaces bounding the wetting lm is low. This is a chieved by studying the wetting of different alkanes on water, in the prese nce of a surfactant. The results agree well with the theoretical calculatio n of the fluctuation repulsion of a membrane under vanishing surface tensio n.