INVESTIGATION ABOUT THE EXTENT OF MODIFICATION EFFECT ON MODIFYING THE SURFACE OF THREE-DIMENSIONAL SHAPED MATERIAL BY COLD PLASMA

抄録

We irradiated the reactive plasma to the carbon material having a three dimensional shape in order to examine about the extent of surface modification. In this case, it is problem what region is improved and whether the surface is modified uniformly. The box which has a small hole on upper side was used as a sample, which consists of the GC plate, a spacer and a upper plate. The characteristics on the inner surface of GC plate which was changed by plasma entering from its hole were investigated. The estimation of modification effect was carried out by contact angle to water at some points on its surface. When the sample was treated by plasma, the upper plate thickness t, the hole diameter 2r and pressure during plasma treatment were varied. As the thickness t was larger, effect on modifying the inner surface of GC plate was smaller and there was larger difference in its effect between the center and edge of the plate. In case that hole diameter 2r was varied, modification effect was increased and became uniformly by widening a hole. Even if 2r was considerably small (0.5mm) with 1mm of thickness, the modification effect was fairly large, which the contact angle decreased from 90°(untreated value) to 43° at the center (x=0mm) by plasma treatment. This is considered that the extent of modification effect depends on the quantity or condition of modification sources, which relate to the balance among the consumption, the movement and the generation of modification sources. And the interesting results was obtained that as the value of pressure was higher, all over the GC surface was more improved. It may be found that the inner part of the hole is not plasma but sheath region, and the modification source is radical in this case.