Effect of Surface Fluorination of Electrode for Charge Injection in Polyethylene

Several fluorinated polyethylene surface studies have proved that the fluorination reaction can effectively prevent charge from injecting into the sample. Therefore, this paper explores a new question: Whether the surface fluorination treatment of poly(ethylene-co-vinyl acetate) (EVA) electrode loaded with carbon black particles can effectively suppress the injection of charge from the electrode into the polyethylene flat? In this study, the fluorinated EVA+CB electrode is heat-pressed to the surface of the polyethylene to prepare a sample. Then the comparative experiments to measure the space charge distribution inside polyethylene were carried out using laser pressure wave propagation(PWP) method from the aspects of electrode fluorination time and fluorination temperature. To clarify chemical compositions of the fluorinated surface layers, ATR-IR spectra and scanning electron micrographs of polyethylene plate and different electrodes were performed. The experimental results reveal that a fluorinated layer is formed on the surface of the fluorinated EVA+CB electrode, which blocked the impurities from entering the polyethylene. Impurities generate heterocharge and after being blocked, the charge neutralized with homocharge inside the polymer is reduced, so that the measured charge in the apparent result is greatly increased.