Abstract
Silicone rubber was irradiated with a mixed beam of oxygen cluster and monomer ions or an oxygen cluster ion beam. The contact angle on the surface of the silicone rubbers decreased with an increase in the dose of the beam. The contact angle decreased with increasing acceleration voltage when an oxygen cluster ion beam was irradiated. On the other hand, the low contact angle obtained by the irradiation of oxygen cluster ion beams at acceleration voltages of 6 and 9 kV was realized by the irradiation of a mixed beam of oxygen cluster and monomer ions at an acceleration voltage of 3 kV. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy results indicate that the oxidation caused by the irradiation might be the cause of the decrease in the contact angle.
