Properties of coatings used in electrical insulators modified

Iranian researchers from Tarbiat Modarres University succeeded in the production of self-cleaning coating with many applications in power industries, specially in the zones that are polluted with industrial pollutants. The coating enjoys highly appropriate hydrophilicity and photocatalytic properties in the range of visible light. One of the problems with cable insulators is that as soon as their surface is covered with organic pollutants, they lose their insulation properties and become conductive. Therefore, in this research, self-cleaning coatings have been produced on porcelain substrates. To this end, titania thin films were coated with optimum percentages of tin and niobium metallic cations on porcelain substrate through dip-coating method, and photocatalytic, hydrophilicity, and surface properties of the samples were investigated. The optimum combination of coating solution and optimum process conditions were determined by using Taguchi design. According to the results, the produced coating has nanometric particles with very high specific area. The thickness of the coating is 200 nm, and it significantly increases the efficiency of the photocatalytic reaction in comparison with pure titania coating. Hydrophilicity of titania thin film is better in the presence of Sn cation comparing to the presence of Nb, and the contact angle between water drops and the coating is less. The photocatalytic properties of the coating have been transferred from ultraviolet (UV) light to visible light due to the use of metallic cations. Adsorption of sunlight and activation of photocatalytic process by the coating result in the decomposition of the pollutant. The pollutants are washed from glass surface due to the hydrophilicity properties of the coating. Results of the research have been published in Journal of Sol-Gel Science and Technology, vol. 69, issue 2, February 2014, pp. 412-417.