SURFACE-PROPERTIES OF POLYETHYLENE IMPLANTED WITH N+, F+ AND AR+ IONS

The oxidation processes and surface polarity of polyethylene (PE) impl anted with 65 keV N+, 80 keV F+ and 150 keV Ar+ ions with doses from 1 x 10(13) to 1 x 10(15) cm(-2) were studied by different techniques in order to clarify the role of the implanted-ion mass. The oxygen conte nt in the radiation-damaged PE surface layer, determined from RBS (Rut herford back-scattering) spectra, increases with increasing ion dose, reaches a maximum at a specific ion dose, which is an increasing funct ion of the ion mass, and then decreases. A similar dose dependence was also observed in the concentration of the carbonyl group, as determin ed from IR spectra. The concentration and conjugation length of double bonds produced by ion implantation and measured by UV-visible spectro scopy are increasing functions of the implanted dose and the ion mass as well. The PE surface polarity measured as a polar component of the surface free energy gamma(s)(p) increases monotonously with increasing ion dose and for the doses D greater than or equal to 5 x 10(13) cm(- 2) the approximate relation gamma(s)(p) = A lg D + B holds with slope A being a decreasing function of the ion mass.