LONG-RANGE ATTRACTIVE FORCE BETWEEN HYDROPHOBIC SURFACES OBSERVED BY ATOMIC-FORCE MICROSCOPY

There is evidence from atomic force microscopy for a long-range attrac tive force between hydrophobic surfaces that is virtually identical to that observed with the surface forces apparatus. This force is presen t in the nonaqueous solvent ethylene glycol. A possible molecular mech anism involves in-plane polarized domains of solid-like monolayers ads orbed on mica, and a theoretical model has been developed that account s for many of the observations.