RBS study of oxidation processes in polypropylene and polyethylene implanted with fluorine ions

Abstract

The oxidation on polypropylene (PP) and polyethylene (PE) samples implanted with 50–200 keV F + ions to the ion fluences from 1 × 10 11–1 ×10 15 cm −2 was studied using standard Rutherford backscattering (RBS) technique. The implanted samples were stored in the air and in darkness, and the oxidation process was followed by repeated RBS measurements in the time interval 1–150 days after the ion implantation. In PP, the oxidation, initially limited to the radiation damaged surface layer, proceeds steadily inward and a homogeneous oxidized layer is built up. The well defined sharp interface between the oxidized layer and the bulk PP moves inside with a mean velocity of 4.0 × 10 −5 nms −1. The ion implanted PE samples are homogeneously oxidized from the sample surface up to the depths accessible to RBS technique. The surface ratio of oxygen and carbon atomic densities in ion implanted PP and PE samples increases from about 0.06 for the ion fluences below 1 × 10 14 cm −2 to about 0.17 for higher ones.