Multifunctional Integrated Coating Design and Self-Cleaning Mechanism for Composite Insulators in High-Altitude Heavily Polluted Areas

Composite insulators in extreme environments (high-altitude, freezing temperatures, and industrial pollution) face severe contamination accumulation and ice coating, leading to flashover risks. This study develops a multifunctional integrated coating with simultaneous anti-icing, pollution resistance, self-cleaning, and UV durability, and reveals its self-cleaning mechanism.

Coating Design Innovations

1. Graded Functional Structure

  - Base layer: Silicone-modified resin (Adhesion ≥5MPa)  

  - Intermediate: SiO₂/TiO₂ nanoparticle-reinforced hydrophobic layer (WCA＞150°)  

  - Surface: Photocatalytic fluorosilicone polymer (40% visible-light efficiency boost)

2. Key Performance Features

  - Nano-engineered surface reduces ice adhesion to ＜50kPa  

  - Photocatalytic degradation rate＞90% for organic pollutants in 6h  

  - Contact angle hysteresis ＜5° enables efficient droplet rolling

 Self-Cleaning Mechanism

1. Physical Action

  - Superhydrophobicity enables spherical droplet rolling (slide angle＜5°)  

  - Micro/nano hierarchical structures minimize contamination adhesion points

2. Chemical Action

  - TiO₂@MoS₂ heterojunction generates reactive oxygen species (·OH yield: 0.28μmol/L·min)  

  - Mineralizes organic pollutants into CO₂/H₂O, resolving oil-based adhesion

Field Application

Pilot deployment at 3800m altitude (Central Tibet Grid):  

- Cleaning frequency reduced from 12 to 2 times/year  

+35% flashover voltage under freezing rain  

- Predicted service life＞8 years (vs. 5 years for conventional RTV)  

Conclusion

This integrated coating achieves dual "passive anti-fouling + active purification" through multi-scale material design, providing a groundbreaking solution for power grid safety in extreme environments.