Super-hydrophilization of a Fused Silica Glass Surfaces by Using an Atmospheric Pressure Plasma Jet

Abstract

An atmospheric pressure plasma jet was used for the surface modification of fused silica glasses. The length of an atmospheric pressure argon plasma jet generated at an applied voltage of 10 kV, at a frequency of 9 kHz and at an argon gas flow rate of 10 L/min was approximately 3 cm. The wettability of the glass surface was improved by the irradiation of the argon plasma jet. The contact angle of a water drop on the glass surface after the argon plasma jet irradiation for 10 s decreased from 70 to 7 degree, indicated that the glass surface after the irradiation became super-hydrophilic. The super-hydrophilicity changed to ordinary hydrophilicity after one hour and the hydrophilicity was kept three weeks on the glass surface. From the results of XPS measurements, the super-hydrophilicity with irradiation was attributed to the removal of carbon atoms (organic compounds) adsorbed on the glass surface.