An X-ray diffuse scattering study of domains in F(CF 2 ) 10 (CH 2 ) 2 OH monolayers at the hexane-water interface

X-ray off-specular diffuse scattering is used to directly probe the statistical distribution of domains in monolayers of F(CF 2 ) 10 (CH 2 ) 2 OH adsorbed at the hexane-water interface. These domains appear very near a transition from a monolayer solid to gas phase. The domains have a nearly constant radius of ≈ 1.5 μm and a nearest-neighbor separation that varies from 2 to 8 μm with temperature. Evidence that the domains are of equilibrium size suggests that the domain line tension, λ t ≈ 3 × 10 −11 N, can be determined.