Influence of plasma-treated nanoparticles on space charge accumulation in epoxy resin insulation

Polymeric nanocomposites have drawn tremendous interest in the field of high voltage engineering as they demonstrate promising electrical insulation performance. It has been reported that atmospheric-pressure plasma-treatment on the nanoparticles is able to improve the electrical insulation properties of the fabricated nanocomposites. In the present paper, we study the level of space charges in epoxy resin/silica nanocomposites synthesized with plasma-treated nanoparticles. Specifically, a custom-made pulsed electro-acoustic (PEA) detection system measured the distribution of space charges in nanocomposite samples. Nanocomposites with as-received or plasma-treated nanoparticles at loading rates of 1, 2, and 3 wt % were fabricated. Measurements were taken at 15 and 45 minutes during which the samples were being polarized with a direct current (DC) electric field of 24 kV/mm. The level of space charges in different samples were compared and analyzed by using the original experimental data. The result suggests that the space charge distribution in the nanocomposites decreases at higher loading rates. The space charge accumulation in the plasma-treated nanocomposites behaves in a different manner as compared to non-treated nanocomposites at different loading rates. An optimal loading rate corresponding to the minimum level of space charges was also suggested for the nanocomposite with plasma-treated silica.