Super-hydrophobic silicone rubber for outdoor electrical insulation

The location mismatch of power production and consumption makes the large capacity energy transmission rather necessary. Overhead transmission line has always been the major approach to power delivery, where insulators are essential. Large-scale pollution flashover of insulators used to be the greatest threat to power system. Therefore, silicone rubber (SR) based insulator was introduced due to its hydrophobicity and now gets increasingly popular. However, the hydrophobicity degradation of SR during operation has been widely reported, significantly affecting the long-term performance. Therefore, super-hydrophobic SR was proposed for enhancement. In this paper, the recent progresses towards the fabrication techniques of super-hydrophobic SR are reviewed, including etching, moulding, and coating. The simplicity of fabrication procedure and the hydrophobicity of sample are paid most attention to. As a consequence, fabricating super hydrophobic insulator by coating is most likely to be used, and coating of nano-SiO2 with PDMS/epoxy resin transition layer is recommended. No rigorous condition is needed during the fabrication process, and the cost of coating is only around 1 $/m2. Besides, the durability of coating under multiple stresses was illustrated, which confirms its feasibility for actual service. Moreover, based on the current research, several prospects are proposed towards the investigation on super-hydrophobic coating.