The surface phenomena of silicone rubber under the influence of impinging plasmas

Surface characteristic properties of silicone rubber change under the conditions of a plasma impingement, especially the hydrophobicity. After a period of time, however, there is a certain amount of recovery of the water repellency. The object of the authors´ work is to study the factors which influence this surface phenomena. It was found that the time duration of exposure to surface plasma, the corona intensive factor and the configuration of electrodes played some important part in the change of a sample´s water repellency. The longer the time of exposure to the plasma, or the closer the distance of the sample surface to the plasma source, or the stronger the plasma intensity, the more severe was the decrease of the water contact angle on the sample surface. The lower the contact angle after plasma impingement, the higher was the relative recovery rate of the surface water repellency. The change of the surface chemical characterisation before and after the plasma impingement was detected. The possible reasons for the self-recovery of the surface hydrophobicity after exposure to plasmas are discussed