Spontaneous, scalable, and self-similar superhydrophobic coatings for all-weather deicing

Herein, we proposed and demonstrated a facile and scalable strategy to fabricate multifunctional self-similar superhydrophobic coatings. Firstly, a hydrophobic cationic cellulose derivative containing imidazolium cation was synthesized by a controllable derivatization. It could effectively disperse one-dimensional (1D) multi-walled carbon nanotubes (MWCNT), because the imidazolium cations formed cation–π interactions with MWCNT. Further, the synergy effect of the cationic cellulose derivative and MWCNT dispersed two-dimensional (2D) reduced graphene oxide (rGO) to obtain a three-components nano-dispersion. Finally, via a simple spaying process, a superhydrophobic coating with self-similar micro-nano structures spontaneously formed from inside to outside, owing to the various nanostructures with different shapes and sizes in the dispersion and the adhesive effect of the cellulose derivative. This superhydrophobic coating was easy to scale, and exhibited superior stability owing to the renewal micro-nano structures. It retained the superhydrophobicity even if it was treated by rubbing for 1500 times. Moreover, it had outstanding photo-thermal and Joule-heating performance, because of the strong solar absorption and high electrical conductivity of MWCNT and rGO. It provided both passive anti-icing and active deicing effects. Thus, it could achieve all-weather anti-icing for wind power generators under sunlight and low voltage conditions. Such facile preparation method and multifunctional renewable superhydrophobic coating hold great application prospects.