Improving Surface flashover Performance of LDPE by Dopamine Based on Bionic Technology

Abstract

In this paper, dc vacuum surface flashover properties of low density polyethylene (LDPE) film covered with dopamine (Dp)-silver (Ag)-Dopamine (Dp) sandwich structure on the surface by immersing LDPE in dopamine solution(6h), silver nitrate (0.5h, 1h, 2h, 4h) and dopamine (24h) solution in order was researched. Scanning electron microscopic (SEM), surface potential decay (SPD) and Keithley 6517B were used as characterization methods to evaluate surface morphology, surface trap distribution and surface conductivity separately. These parameters may reveal the influence mechanism of Dp-Ag-Dp sandwich structure on samples surface. SEM images shows that nano-Ag particles attaching on the surface of samples and their size and quantity become larger with silver nitrate solution immersing time prolonging. SPD results indicates that both shallow and deep trap depth move to the deeper direction with increasing modification time, while shallow trap and deep trap density decreases first and then increases with the increase of treating time. Surface conductivity enlarges over silver nitrate processing time. For dc vacuum surface flashover voltage, the results presents that its value increases with silver nitrate treatment time when the samples were soaked in silver nitrate solution for less than 2h. It can be concluded that by modifying surface parameters like trap distribution and surface conductivity covering LDPE film surface with dopamine-silver-dopamine sandwich structure can change dc vacuum surface flashover performance.