Competitive and synergistic effects between excimer VUV radiation and O radicals on the etching mechanisms of polyethylene and fluoropolymer surfaces treated by an atmospheric He–O₂post-discharge

Abstract

Among various surface modification techniques, plasma can be used as a source\nfor tailoring the surface properties of diverse materials. HDPE and\nfluoropolymer surfaces have been treated by the post-discharge of an\natmospheric RF-plasma torch supplied with helium and oxygen gases. The\nplasma-treated surfaces were characterized by measurements of mass losses,\nwater contact angles, x-ray photoelectron spectroscopy and atomic force\nmicroscopy. This experimental approach correlated with an optical\ncharacterization of the plasma phase allowed us to propose etching mechanisms\noccurring at the post-discharge/polymer interface. We discuss how competitive\nand synergistic effects can result from the oxidation and/or the roughening of\nthe surface but also from the excimer VUV radiation, the He metastable species\nand the O radicals reaching the plasma-polymer interface.\n