Structure and composition of the surface layer in polymers modified by elemental fluorine

A model is proposed for the layered structure of a polymer surface modified by elemental fluorine mixed with helium. The composition of the modified surface layer has been determined, and the thermodynamic compatibility of the surface layer, transition layer, and unmodified bulk of the polymer has been studied. The thickness of the modified layers has been calculated as a function of the fluorination conditions. (C) 2004 Wiley Periodicals, Inc.