Rigid surface films

A new type of squeeze film apparatus is described which thins a liquid between a metal surface and liquid mercury. By this means contamination by dirt is circumvented. The thickness of the film is determined from capacitance measurements. Anomalous layers up to 2.5 x 103 nm are formed when the liquid (cetane) contains an additive (1/10 % stearic acid) which reacts with the metal, which here is chromium or iron. Platinum forms no such film. A non-reactive additive, cetylamine, gives no film with Fe, Cr or Pt, even though the material is highly surface active. Tests at different temperatures reveal a positive relation between temperature and thickness. This is evidence that the film is organized by chemical rather than 'physical forces. It also allows a figure to be obtained for the energy of activation of the layer. The apparatus will measure down to 1.8 nm in the case of a retracted monolayer. Evidence is put forward pointing towards anomalous surface viscosities.