Haidong Kim

Polymer surface modification by plasma source ion implantation

Abstract The plasma source ion implantation technique has been used to improve the wetting property of polymer surfaces. The modified polymer surfaces were evaluated with a contact angle meter to note the change of water contact angles and their variations with time. The oxygen-implanted samples showed extremely low water contact angles of 3° compared with 79° of unimplanted ones. Furthermore, the modified surfaces were relatively stable with respect to aging under ambient conditions. Time-of-flight secondary-ion mass spectrometry(TOF-SIMS) and scanning auger electron spectroscopy were used to analyze the implanted surfaces. From TOF-SIMS analysis it was found that oxygen-containing functional groups had been formed on the implanted surfaces. On the other hand, the CF 4 -implanted samples turned out to be more hydrophobic than unimplanted ones, giving water contact angles exceeding 100°. The experiments showed that plasma source ion implantation is a very promising technique for polymer surface modification, especially for large area treatment.

Plasma source ion implantation of nitrogen, carbon and oxygen into Ti-6Al-4V alloy

Abstract Plasma source ion implantation (PSII) has been under extensive research as an innovative technique for ion implantation of three-dimensional objects. A PSII device has been built and used to study nitrogen, carbon and oxygen ion implantation into Ti-6Al-4V orthopaedic alloy. The r.f. plasma generated using an antenna located inside the vacuum chamber was measured to have densities of 10 9 –10 10 cm −3 at 0.5 mTorr of neutral pressure. The target bias voltage and current during implantation were monitored with a voltage divider and a current transformer. The bias voltage was found to have a rise time of about 5 μs and flatness over the pulse width of 20 μs. The Auger analysis of the implanted samples was shown to have depth distributions typical for ion implantation and the implanted layers were found to have undergone chemical state changes. The implantation time dependences were different for nitrogen, carbon and oxygen ion implantation. The implanted samples showed higher hardnesses especially at low loads in the order of oxygen, nitrogen and carbon ion implantation.