Enhanced interface effect on charge dynamics and thermal properties of epoxy nanocomposites with plasma-treated nano-alumina at high temperature

Abstract

To improve the interface effect between the nanoparticles and the host matrix, this study used the plasma generated by the dielectric barrier discharge device to treat the surfaces of nanoparticles. The epoxy resin (EP)/alumina nanocomposites with 10 wt% nano-alumina were prepared. The dispersion and treatment results of the nanoparticles were characterized by scanning electron microscopy. The space charge characteristics, dielectric properties, and electrical conductivity of prepared samples at 25 ℃ and 100 ℃, respectively were investigated. Thermal analysis was further carried out to reveal the enhancement effect of the plasma treatment. The results suggest that the nano-alumina with plasma treatment was uniformly distributed in the matrix, whereas the agglomerations occurred in the untreated nanocomposites with more hydroxyl groups. Nanocomposites filled with untreated 10 wt% nano-alumina particles exhibited higher space charge accumulation with distorted electric field, permittivity, tanδ and electrical conductivity. On the other hand, plasma treatment helped inhibit the space charge accumulation, permittivity, tanδ, and improve thermal stability of the nanocomposites. It is postulated that the plasma treatment can improve the thermal stability of the sample by enhancing the interface effect between the nano-alumina particles and EP matrix, leading to the enhancement of the electrical performance of the EP nanocomposites at high temperature. The interface effect mechanism of nano-alumina in the nanocomposites is summarized to explain the above improvement.