UV accelerated aging of RTV/SiO2 nanocomposites: Study on surface microstructure, hydrophobicity, and electrical properties

RTV-SiR coatings are widely used to preserve ceramic insulators in high voltage power lines. These coatings enhance insulators' resistance to environmental factors, such as contamination and moisture, as well as UV irradiation. The functional lifespan of RTV-SiR could be improved via addition of different nanoparticles such as SiO2. In this research, the effect of nano silica content on surface microstructure, hydrophobicity, and electrical properties of RTV-SiR before and after UV irradiation was studied by FESEM, AFM, surface roughness, contact angle, hydrophobicity transfer ability, dielectric parameters, and electric resistance. Results demonstrated that the optimal percentage of filler in the composite could make an appropriate surface roughness and increases hydrophobicity. Also, the excessive destruction of the RTV-SiR caused by UV irradiation is prevented by nano silica. Moreover, the contact angle of the coating reached the first level in a shorter period of time after applying pollution thanks to the presence of nano silica. Eventually, composite samples illustrated better performance than pure RTV-SiR, and the best properties were observed in samples containing 3 wt% silica.