Insight into the remaining high surface energy of atmospheric DBD plasma-treated polyethylene web after three months’ aging

In this paper, we report the modification of polyethylene (45 μm in thickness) webs through a roll-to-roll dielectric barrier discharge plasma treatment in an open atmospheric environment. Our work differs from the normal adopted corona discharge treatment at an atmospheric pressure, in that three monomers: allylamine, acrylic acid, and ethanol, are inlet into the discharge zone by argon (Ar) carrier gas. As a comparison, Ar plasma treatment is also carried out. We focus on the aging properties of treated plastics in the open air. It is found that the modified webs can retain the surface energy as high as 50.0±1 mN m^-1 for more than three months. After characterization of the as-prepared and aged samples by the surface roughness, the wettability, and the chemical structure, the mechanism of retaining high surface energy is then presumed. We think that the initial high surface energy just after plasma treatment is correlated to the grafted functional groups, while the over 50.0 mN m^-1 remaining surface energy after three month aging is due to the stable concentrations of oxygen-contained and nitrogen-contained groups by post-reaction on the surfaces.