Structure and Depletion at Fluoro- and Hydro-carbon/Water Liquid/Liquid   Interfaces
  The results of x-ray reflectivity studies of two oil/water (liquid/liquid) interfaces are inconsistent with recent predictions of the presence of a vapor-like depletion region at hydrophobic/aqueous interfaces. One of the oils, perfluorohexane, is a fluorocarbon whose super-hydrophobic interface with water provides a stringent test for the presence of a depletion layer. The other oil, heptane, is a hydrocarbon and, therefore, is more relevant to the study of biomolecular hydrophobicity. These results are consistent with the sub-angstrom proximity of water to soft hydrophobic materials. 
Kaoru Kashimoto, Jaesung Yoon, Binyang Hou, Chiu-hao Chen, Binhua Lin,   Makoto Aratono, Takanori Takiue, and Mark L. Schlossman