2014/08/18 by Edl Schamiloglu · 1 citation
Materials Science · Medicine · Engineering · #High voltage insulation and dielectric phenomena #Plasma Applications and Diagnostics #Plasma Diagnostics and Applications
paper · doi:10.1063/1.4893884
openalex publication_date 2014/08/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/02
Polymer materials, such as polymethylmethacrylate (PMMA), are widely used as insulators in vacuum. The insulating performance of a high-voltage vacuum system is mainly limited by surface flashover of the insulators rather than bulk breakdown. Non-thermal plasmas are an efficient method to modify the chemical and physical properties of polymer material surfaces, and enhance the surface insulating performance. In this letter, an atmospheric-pressure dielectric barrier discharge is used to treat the PMMA surface to improve the surface flashover strength in vacuum. Experimental results indicate that the plasma treatment method using Ar and CF4 (10:1) as the working gas can etch the PMMA surface, introduce fluoride groups to the surface, and then alter the surface characteristics of the PMMA. The increase in the surface roughness can introduce physical traps that can capture free electrons, and the fluorination can enhance the charge capturing ability. The increase in the surface roughness and the introduction of the fluoride groups can enhance the PMMA hydrophobic ability, improve the charge capturing ability, decrease the secondary electron emission yield, increase the surface resistance, and improve the surface flashover voltage in vacuum.