Long-term Durability of Stearic Acid Silicon Dioxide Nanoparticle Superhydrophobic Coating on Aluminium Alloy Overhead Line Conductors

The accumulation of ice can lead to serious damage and failure of overhead line systems due to the additional mechanical loads applied during icing events. CIGRE TB361 has detailed a range of advanced superhydrophobic coatings and this paper details the replication and optimisation of the manufacturing procedure to coat overhead line samples with a stearic acid-based coating. The solution was loaded with Silicon Dioxide (SiO2) nanoparticles and achieved a sliding angle of 3° and a contact angle of 169°on aluminium substrates. The paper also describes several ageing tests, including thermal ageing, corona exposure, ultraviolet radiation, and outdoor environmental exposure. Samples were characterised using different techniques such as contact angle measurements and microscopy tests before and after each ageing test. High temperature and corona discharge were shown to have a strong degrading effect on coating's superhydrophobicity. Ultraviolet exposure and outdoor tests changed the wettability performance of samples and led to ‘sticky’ surfaces with high contact angle hysteresis. Tests indicated that the coating has poor performance under difference ageing conditions and is unsuitable for deployment onto overhead power lines.