Polyurea-based hydrophobic durable coatings with carbon nanotubes for passive anti-icing and active de-icing

Ice accumulation can cause tremendous economic losses and lead to severe safety problems. To mitigate negative impact of icing, both active de-icing and passive anti-icing materials have been designed and fabricated. Traditional active electro-thermal de-icing methods suffer from high energy consumption and low efficiency, while passive hydrophobic anti-icing surfaces meet the challenges of robustness during practical application due to outdoor abrasion and UV radiation. Herein, we developed the composite coatings which integrate fluorinated hydrophobic polyurea coating and electro-thermal carbon nanotubes (CNTs) film to achieve the effect of both passive anti-icing and active de-icing. Based on the strategy, the fluorinated polyurea coating modified with polydimethylsiloxane (PDMS) and silicone oil exhibited the lowest ice adhesion strength of 32.8 kPa at −20 °C via the synergistic effects of low surface energy and interfacial slippage, compared with 83.0 kPa for unmodified polyurea coating. The prepared hydrophobic coating exhibited excellent robustness property by adopting the combination of soft and hard molecular segments. Even after 1500 abrasion cycles, 288 h UV radiation, 288 h salt spray corrosion or 7 days outdoor experiment, the ice adhesion strength of fluorinated polyurea coating maintained ∼38 kPa, demonstrating excellent durability for outdoor applications. The composite coating combined fluorinated polyurea coating and CNTs film also displayed highly efficient active de-icing performance. Under the same voltage, the ice cubes attached to the fluorinated polyurea coating surface dropped after heating 730 s at −20 °C, whereas no detachment occurred for unmodified polyurea coating even after heating 3600 s. These findings demonstrate that hydrophobic composite coating can provide an efficient and durable anti-/de-icing solution with promising applicability in practical applications.