Structure of Confined Films of Chain Alcohols

The structure of thin films of simple chain alcohols (1-octanol and 1-undecanol) confined between two atomically smooth mica surfaces has been investigated using a surface forces apparatus. Contact angle measurements and optical sum frequency generation were used for additional characterization. In both systems, the substrate−molecule interaction leads to a strongly bound first layer on each surface. Additional liquid organizes into highly compressible bilayers, which could be expelled by applying sufficiently high pressure.