Investigation of electrical properties of silica-reinforced RTV nanocomposite coatings

This study investigates the effect of various amounts of silica nanoparticles on electrical properties of RTV-SiO₂ nanocomposite. The effect of increasing the amounts of filler in the RTV1 polymer matrix on the dispersion and dispersibility of nanoparticles has also been investigated through microscopic images. SEM images demonstrated that surface roughness excessed with increasing filler percentage, so that the non-uniformed distribution of the fillers will occur and the surface morphology will change. Electrical results indicated an increase in dielectric loss factor and a decrease in volume resistance via addition of 1, 3, and 5%wt nano-silica in composites. Also, there was a significant decrease in the dielectric strength by adding 3%wt of nano-silica. However, the dielectric constant and surface resistance did not change. Tracking test demonstrated that the erosion resistance of the sloping surface was greatly improved by increasing the nano-silica content, and this is very important for the application of this specific nanocomposite as a high-voltage insulators coating.