Surface chemical and nanomechanical alterations in plasma immersion ion implanted PET

Abstract

Polyethylene terephthalate) (PET) surface was treated by plasma immersion ion implantation (Pill or Pl3) in nitrogen. The treatment conditions like acceleration voltage, ion fluence and fluence rate were varied systematically. The Pill-induced alterations in the surface chemical composition and bonding of the constituent elements were studied by XPS. Nanoindentation and nanoscratch measurements were applied to investigate the related changes in the hardness, elastic modulus and wear resistance. Nitrogen Pill treatment of PET led to incorporation of nitrogen and decrease of surface O/C ratio. The bulk plasmon loss energy of the C 1s peak increased, implying compaction of the surface layer. Pill treatment increased the mean surface roughness and hardness (H), and decreased the elastic modulus (E). Process conditions were found, under which a four-fold increase was obtained in the wear resistance. Improvement in wear resistance was accompanied by increase in the H/E ratio. Copyright © 2008 John Wiley & Sons, Ltd.