INVESTIGATION OF EFFECTS OF PLASMA COMPOSITION ELEMENTS BY THE CONTROLLED PLASMA ON THE SURFACE MODIFICATION OF THE CARBON MATERIAL

This investigation was conducted on the surface modification of the carbon material by the controlled R.F. glow discharge plasma with the objective of investigating the effects of plasma composition elements (plasma parameters). We looked into the effects of the light radiated from the plasma and the ions in the plasma mainly. The surfaces of the carbon material, which was glassy carbon (GC), was treated by the Ar plasma. The contact angles for water to the carbon material surface after the plasma treatment was measured. Moreover, its surface was analyzed by using Raman spectroscopy and ESCA. Also, we observed it by SEM. Ar plasma treatment makes the surface of the carbon material to hydrophilic and the contact angle decreased. By the effects of light radiated from the plasma, the contact angle of its surface after the plasma treatment decreased for the first time, and then increased with time. It is considered that the effect of light is the formation of the radical into its surface mainly. In three cases that the sheath voltage is changed, the ion density is varied and the plasma-treatment time is altered, the variation of the contact angle shows a similar tendency one another. It indicated that the effects of the three elements (the energy, the quantity and the number of times of the ion collision onto the surface of the carbon material) on the contact angle were considered to be the same.