Glow discharges of oxygen and nitrogen were applied to low density
polyethylene thin films in order to study accelerated oxidation and
nitridation in the polymer. The studies were focused on the morphologic,
crystalline and hydrophilic evolution promoted by plasma exposure. The
particular chemical characteristics of the gases and the constant impact of
high-energy particles on the surfaces produced different types of erosion.
Oxygen plasmas produced the release of fragments from the polymeric surface
which created fibered textures and nitrogen plasmas resulted in folded
morphologies of nano and micro dimensions on polyethylene. The plasmas of
both gases increased and decreased the crystallinity in the polymers,
between 33% and 57%, with similar tendencies, differing only in the
percentage of crystallinity. The plasma exposure produced a decrease in the
contact angles of water on polyethylene in the first 30 min of plasma, from
70% in the untreated polymers, to 45% and 35% as a consequence of
the polar groups added to the surface.