Inorganic nanofilms for surface charge control on polymer surfaces by atmospheric-pressure plasma deposition

An effective surface charge removal is critical to diverse applications of polymer and other soft organic materials in electrical devices and systems. Here, we report on the application of atmospheric pressure dielectric barrier discharge (AP-DBD) to deposit SiO_x thin films to improve the surface charge dissipation on an epoxy resin surface. The SiO_x nanofilms are formed at atmospheric pressure, with the replacement of organic groups (C-H, C=O and C=C) with inorganic groups (Si-O-Si and Si-OH) within the thin surface layer. After the plasma deposition, the initial surface charge decreased by 12% and the surface charge dissipation was accelerated. The flashover voltage which characterizes the insulation property of the epoxy resin is increased by 42%. These improvements are attributed to the lower density of shallow charge traps introduced by SiO_x film deposition, which also corresponds to the surface conductivity increase. These results suggest that the SiO_x deposition by AP-DBD is promising to accelerate surface charge dissipation. This method is generic, applicable for other types of precursors and may open new avenues for the development of next-generation organic-inorganic insulation materials with customized charge dissipation properties.