Potential of slippery liquid infused porous surface coatings as flashover inhibitors on porcelain insulators in icing, contaminated, and harsh environments

Abstract

Humidity and pollution deposition on the surface of porcelain insulators affect the electrical field distribution and their performance which may lead to partial discharge and decreasing flashover voltage. Thereby one essential aspect of insulator designing is their surface science and surface wettability. To address these challenges, in this study robust omniphobic coatings were designed which can repel water and oil droplets as well as other contaminant particles from the porcelain insulators surface. In this regard, slippery liquid infused porous surface (SLIPS) coatings were applied on the porcelain substrate by infusing perfluorinated liquid lubricants into 200 %-stretched Teflon tape cover or fluoro-silanized porcelain. The surface of the designed transparent coatings repelled water, olive oil, kaolin, sodium chloride microparticles, and ice. The applied coatings exhibited low contact angle hysteresis (Δθ ≤ 5°) and a low sliding angle (α ≤ 7°) for water and olive oil droplets. SLIPS coatings showed good stability to extreme environments like immersion into acid, base, brine solutions, UV radiation and withstood at 4.5 kV inclined plane test without failure after 6 h. So, the modified SLIPS can be used as effective coatings in the porcelain insulators surface engineering.