Photothermal dual-shell PCM microcapsules for superhydrophobic anti-icing/deicing coatings

Ice accretion on high-voltage transmission lines can easily cause conductor breakage and tower collapse, posing severe threats to power grid safety. Photothermal superhydrophobic coatings enable solar-driven active deicing and superhydrophobic passive anti-icing, yet the anti-icing/deicing efficiency decreases significantly at night or under prolonged overcast, rainy, and low-temperature conditions. In this study, dual-shell structured TSP photothermal phas e-change composite microspheres were prepared via a sol-gel method combined with in situ polymerization, and a spray-coating process was employed to construct a composite coating integrating photothermal, latent-heat-storage, and superhydrophobic functions. The results demonstrate that the introduction of an appropriate amount of aniline allows TSP-A 0.5 microspheres to form a uniform micro/nano rough structure on the coating surface, yielding a water contact angle of 164.8°. Under light irradiation, the surface temperature rapidly rises to 99.3 °C, and the photothermal conversion efficiency reaches 94.5%. Meanwhile, the n -tetradecane core provides effective latent-heat storage and release, with TSP-A 0.5 exhibiting a melting enthalpy of 194.80 J/g, an energy release efficiency of 95.72%, and stable thermal performance over 100 thermal cycles. Benefiting from the synergistic effect of the superhydrophobic interface, photothermal heating, and phase-change heat release, the droplet freezing time on the TSP-A 0.5 coating is extended to 306 s, which is 14.5 times that of the bare aluminum substrate, and the photothermal deicing time is shortened to 64 s. Moreover, the coating exhibits a low-frequency impedance modulus of 8.01 × 10 7 Ω·cm 2 , demonstrating favorable corrosion resistance. This work provides a new strategy for all-weather protective materials for transmission lines.