Surface modification of silicone rubber by CF4 radio frequency capacitively coupled plasma for improvement of flashover

Abstract

Abstract The flashover performance of insulating materials plays an important role in the development of high-voltage insulation systems. In this paper, silicone rubber(SIR) is modified by CF4 radio frequency capacitively coupled plasma(CCP) for the improvement of surface insulation performance. The discharge mode and active particles of CCP are diagnosed by the digital single lens reflex and spectrometer. Scanning electron microscopy and X-ray photoelectron spectroscopy is used for the surface physicochemical properties of samples, while the surface charge dissipation, charge accumulation measurement and flashover test are applied for the surface electrical characteristics. Experimental results show that the fluorocarbon groups can be grafted and the surface roughness increase after plasma treatment. Besides, the surface charge dissipation is decelerated and the positive charge accumulation is obviously inhibited for the treated samples. Furthermore, the surface flashover voltage can be increased by 26.67% after 10-minute treatment. It is considered that strong electron affinity of C-F and increased surface roughness can contribute to deepen surface traps, which not only inhibits the development of secondary electron emission avalanche, but also alleviates the surface charge accumulation and finally improve the surface flashover voltage of SIR.