Design robust, degradable and recyclable superhydrophobic materials

• A strategy is presented to design robust and recyclable superhydrophobic materials. • Degradation and efficient recycle of samples are realized in waterborne condition. • Environmental issues caused by hydrophobic particles are also resolved. • The obtained monoliths possess both mechanical stability and chemical tolerance. Superhydrophobic materials have many exceptional properties e.g. self-cleaning, anti-icing; to address the increasing demands of their practical usage, most research have been focused on how to improve their robustness. However, it becomes increasingly challenging to recycle robust superhydrophobic materials for their high mechanical, chemical and thermal durability. Here we develop a strategy to synthesize and recycle robust superhydrophobic composites that consist of hydrophobic particles (HPs) and poly hexahydrotriazine (PHT). The superhydrophobic PHT-HPs composites demonstrate high mechanical and chemical robustness, which had a wear rate of only 1.90 wt% in a 30-min ball-on-disk wear test, and retained superhydrophobicity after 100,000 cm of sandpaper abrasion and 3-himmersion in acid and alkali solutions. Tiny volume of ethanol was used to pre-wet the superhydrophobic PHT-HPs composites and acted as a “key” to initiate the recycling process, followed by rapid degradation of PHT using waterborne acid solutions. The recycling rate of HPs and PHT were both higher than 90% even after three recycling loops. This strategy is expected to give a new prospective to fabricate degradable, recyclable and robust superhydrophobic materials in an environmental-friendly way, in order to reduce the potential pollution to the environments.