Comparison of the monolayer formation of fluorinated and nonfluorinated amphiphilic block copolymers at the air-water interface. 
Series of fluorinated amphiphilic diblock copolymers poly(ethylene oxide)-b-poly(heptafluorobutyl methacrylate) (PEO-b-PHFBMA) and nonfluorinated analogue copolymers poly(ethylene oxide)-b-poly(n-butyl methacrylate) (PEO-b-PBMA) with different lengths of hydrophobic blocks were synthesized.  Their interface properties at the air-water interface were investigated using surface pressure and X-ray reflectivity (XR) measurements on the Langmuir trough.  The fluorinated species have shown a distinct transition from flat-lying to standing side chains, whereas the nonfluorinated ones have no indication for a significant amount of flat-lying side chains.  The water surface is covered by a single layer, which is proved by XR measurements of PEO-b-PHFBMA.  The obtained thickness and electron density can be related to the hydrophobic part of the copolymer by a simple consistency check: The total numbers of electrons from the fit of the XR curve should agree with the numbers of electrons in the corresponding block.