Fig. 1. Preparation process of epoxy resin sample

Fig. 2. Plasma DBD fluorination modification platform

Fig. 3. Lissajous figure, P＝16.05 W

Fig. 4. Surface potential attenuation characteristic test system

Fig. 5. Surface flashover voltage test system

Fig. 6. Surface profile of epoxy resin before and after treatment

Fig. 7. Roughness test results

Fig. 8. SEM images betore and after fluorination treatment

Fig. 9. XPS test results

Fig. 10. Peak patterns of C element in samples not treated and treated for 5 min then stored for different time

Fig. 11. Water contact angle test results

Fig. 12. Surface free energy test results

Fig. 13. Surface conductivity test

Fig. 14. Initial potential on the sample surface

Fig. 15. Surface potential attenuation test results

Fig. 16. Surface trap characteristic curves

Fig. 17. Test results of flashover voltage