A study on the loss and recovery of hydrophobicity of RTV coating

Room temperature vulcanizing (RTV) silicone rubber coatings have been applied for improvement of outdoor insulation for more than two decades. They provide good hydrophobicity of insulator surfaces, preventing formation of continuous water films. Unfortunately, this property will be lost temporarily during outdoor service. A similar effect can be also obtained on RTV coated surfaces when subjected to artificial treatment, such as water immersion and corona discharge. Silicone rubber surfaces can also regain the lost hydrophobicity after a certain period of time. In this paper, the mechanisms involved in the loss and recovery of hydrophobicity are discussed.