Wet flashover voltage improvement of the ceramics with dielectric barrier discharge

Surface modification techniques with plasma are widely investigated to improve the surface insulation capability of polymers under dry conditions, while the relationship between treatment method, surface physical and chemical properties, and wet flashover voltage is still unclear for inorganic ceramics. In this work, the surface insulation properties of ceramics under wet conditions are improved using nanosecond-pulsed dielectric barrier discharge with polydimethylsiloxane (PDMS) as the precursor. The relationships between PDMS concentration and the water contact angle, dry and wet flashover voltages are obtained to acquire the optimal concentration. The surface charge dissipation test and surface physio-chemical property measurement with SEM, AFM, XPS are carried out to further explore the mechanism of surface insulation enhancement. The results show that film deposition with micron thickness and superhydrophobicity occurs at the PDMS concentration of 1.5%. The dry flashover voltage is increased by 14.6% due to the induction of deep traps, while the wet flashover voltage is increased by 66.7%. The gap between dry-wet flashover voltage is decreased by 62.3% compared with the untreated one due to the self-cleaning effect.