Anti‐icing polyimide thin film with microcolumns fabricated by RIE with cooling and PCVD.

Anti‐icing polyimide (PI) thin films are a promising anti‐icing technology for aircraft. A processing method combining reactive ion etching with cooling and plasma chemical vapour deposition is proposed to fabricate anti‐icing PI thin films with microcolumns (PI‐M). The anti‐icing performance of PI‐M was examined. The apparent contact angle (APCA) was 153° ± 1.4°, and the APCA hysteresis was 8.5° ± 0.5°. The calculated Weber number was high, and a droplet on PI‐M rebounded within 2.56 s, whereas rebounding occurred more slowly on a smooth PI surface (PI‐S). The freezing time of droplets on PI‐M was 70% longer than that on PI‐S. The average ice adhesion force on PI‐M was 42% smaller than that on PI‐S. Repeated measurements of the ice adhesion force on PI‐M demonstrated that it was stable (deviation: ±1 N). The APCA showed that PI‐M is superhydrophobic, which indicates that droplets on PI‐M were in the Cassie state. The droplet bouncing behaviour was explained in terms of horizontal force equilibrium at the interface. The anti‐icing mechanism of PI‐M was modelled using heterogeneous nucleation theory and a contact area model. The results explained the good anti‐icing performance and suggested that PI‐M may have excellent potential for anti‐icing applications. [ABSTRACT FROM AUTHOR]