FLUORINATION OF GRAPHITE SURFACE USING EL ECTRON-CYCLOTRON-RESONANCE PLASMA

Fluorinated carbon, which has low surface energy and better thermal st ability, is applicable to water repellents, lubricants and battery cat hods. In the present paper, we have examined the modification technolo gy of CF4 electron cyclotron resonance (ECR) plasma treatment with rf- induced negative self bias voltage on graphite substrates in order to modify the surface of graphite to fluorinated structure. Especially wi th the purpose of preparating the durable fluorinated surface, we have investigated the treatment process factors, and compared the initial property of the modified surface and the property change with the elap se of time. The larger contact angle value of water than that of PTFE certified that the surface of graphite was modified. A further good re sult has been shown that there occurs only a slight change of the repe lling property with the elapse of time. X-ray photoelectron spectrosco py (XPS) result indicated that the higher the rf-induced negative self bias voltage was, the larger the peak area ratios of CF2 and CF3 spec ies to C-1s spectrum became. It is considerd that the fluorinating rea ction was accelerated by the ion bombardment due to rf-induced bias vo ltage, so that CF2 and CF3 species were formed in the deeper region fr om the surface. As mentioned above, it was found that applying the rf- induced negative self bias voltage on graphite substrates was an impor tant factor to give the modified surface durability.