Polyethylene terephthalate (PET) surface modification by VUV and neutral active species in remote oxygen or hydrogen plasmas

Abstract

Polyethylene terephthalate (PET) are exposed either by VUV photons emitted from oxygen or hydrogen plasmas or by VUV photons and neutral active species from both plasmas. The water contact angle (WCA) of PET surface increased after treatment with H2 VUV + H atoms, due to the cleavage of the oxygen‐containing groups by VUV photons. The WCA decreased for the case of treatment with O2 VUV + O‐related neutral active species, leading to be released the polar groups like −COH or −COOH from the PET surface with a depth of less than about 10 nm. Oxygen‐related neutrals etched the PET film and generated a rough surface which also contributed to the decrease in WCA however no bulk chemical structure obviously changed.