Nano-Silica Coatings and Their Effect on the Hydrophobicity and Electrical Properties of Power Line Porcelain Insulators

Abstract The power line insulators are permanently exposed to various environmental pollutants such as dust and fine particles. This may lead to flashovers and therefore widespread power blackouts and heavy economic damage. One way to overcome this problem is to make the insulator surface superhydrophobic. In this research, the superhydrophobic properties of the insulators were improved by applying room-temperature cured composite coatings consisting of epoxy and hydrophobic nano-silica particles. Either octadecyl trichlorosilane (ODTS) or hexamethyldisilazane (HMDS) was used to coat the silica nanoparticles and make them hydrophobic. Then, the hydrophobic silica was added to a mixture of epoxy resin and hardener. The suspension was applied on the surfaces of a commercial porcelain insulator and cold cured at ambient temperature. The coating increased the water contact angle from ۵۰° to ۱۴۹°. Even after ۲۴۴ h exposure to the UV light, the samples preserved their hydrophobic properties. The adhesion of the coating was rated as ۴B according to the ASTM D۳۳۵۹ standard. The coating decreased the leakage current by ۴۰% and increased the breakdown voltage by ۸۶% compared to the uncoated sample and showed promise for making power line insulators self-cleaning.

Keywords:

Ceramic Insulator , Flashover , Hydrophobic Coating , Nano silica