Aging characteristics and self-healing properties of laser-textured superhydrophobic silicone rubber for composite insulators

摘要

The aging characteristics of laser-treated superhydrophobic silicone rubber surfaces was investigated through accelerated aging tests. It indicated that the superhydrophobic surfaces have excellent anti-aging properties, which is manifested in that even after aging for 1000 h, the contact angles of the superhydrophobic surfaces remain above 140°. The loss of hydrophobicity was caused by defects in the surface microstructures, a decrease in the hydrophobic -CH_3 groups, and an increase in the hydrophilic -OH groups on the surfaces. To avoid the decrease in the hydrophobicity of the prepared superhydrophobic surface, a simple and efficient heat treatment method was adopted to restore its hydrophobicity. After heat treatment at 200°C, the rolling angle of the aged surface was restored to 4.6° with a contact angle of 161.5°. This recovery is mainly attributed to the decrease in the content of the -OH on the rubber surface during the heat treatment. The results also show the sample surface irradiated with a laser fluence of 10.0 J/cm~2 has better anti-aging performance and self-healing properties due to the larger particles and a more distinct micro-nano hierarchical structures, providing a smaller actual illumination area and a larger heating area in the aging and heat treatment process.