Liquid permeation into silicone rubber (SR) may lead to the degradation or complete failure of the composite insulators. Aiming to inhibit liquid permeation, two kinds of superhydrophobic coatings are applied to the SR surface. The liquid permeation properties of SR with different types of liquids are investigated, and the Langmuir diffusion model is applied to analyse the experimental data. The results show that the composite superhydrophobic coating can effectively inhibit liquid permeation by reducing the contact area between the surface and liquid, and the stable structure of the composite coating can maintain the performance after the liquid permeation and effusion. However, the nano-particle coating without the polymer binder experiences severe performance degradation during the immersion test, and it cannot restrain the liquid permeation anymore after it loses the superhydrophobicity. As a validation of the effective protection, the insulation resistivity change was measured. The resistivity decreases sharply for the pristine SR after water permeation; however, the decrease is much smaller for the coated SR. The current study not only provides new insight into the liquid permeation properties of SR with different surface wettability but also suggests an effective measure to prevent liquid permeation into SR.

中文翻译：

---

通过超疏水涂层抑制液体渗透到硅橡胶中，延长使用寿命

液体渗透到硅橡胶（SR）中可能会导致复合绝缘子降解或完全失效。为了抑制液体渗透，SR 表面涂有两种超疏水涂层。研究了SR对不同类型液体的液体渗透性能，并应用Langmuir扩散模型对实验数据进行分析。结果表明，复合超疏水涂层可以通过减少表面与液体的接触面积来有效抑制液体渗透，并且复合涂层稳定的结构可以在液体渗透和渗漏后保持性能。然而，不含聚合物粘结剂的纳米颗粒涂层在浸泡测试中性能严重下降，失去超疏水性后不再能抑制液体渗透。作为有效保护的验证，测量了绝缘电阻率的变化。原始SR在水渗透后电阻率急剧下降；然而，对于带涂层的 SR，下降幅度要小得多。目前的研究不仅为不同表面润湿性的SR的液体渗透特性提供了新的见解，而且还提出了防止液体渗透到SR中的有效措施。