Structural Design and Interface Peeling of Superhydrophobic Coatings for the Recycling of Waste Coated Textiles

The three-dimensional permanent cross-linked network formed by cross-linkers after curing can endow coated fabrics with excellent mechanical properties and washing resistance. However, their insoluble and nonmelting nature makes it challenging to peel the coatings from the fabric surface, seriously hindering the recycling and reuse of waste textiles. To address this issue, this study successfully constructed a fluorine-free superhydrophobic coating on cotton fabric that features mechanical robustness, high durability, self-healing capability and on-demand peelability by incorporating covalent adaptable networks (CANs) consisting of imine and C–N bonds into the superhydrophobic coating system. The coatings are fabricated through the aldehyde-amine Schiff-base reaction between polylysine and aldehyde-modified cotton fabric, as well as the Michael addition reaction with styrene–butadiene rubber (SBR) emulsions. Benefiting from the mechanical reinforcement of the CANs, the coated fabrics exhibit excellent washability and sanding abrasion resistance; meanwhile, thermal-induced dynamic exchange of the CANs can heal coating damages, further enhancing the durability of the superhydrophobic coating. In addition, leveraging the acid-triggered dissociation characteristic of dynamic imine bonds, the coating achieves gentle peeling (∼92.4% peeling rate) after prewetting with ethanol, acid treatment, and scrubbing with continuous water. The peeling solution is environmentally friendly and causes moderate damage to the fibers (∼26%). This study provides a viable pathway for the design of next-generation coating systems and the recycling and regeneration of waste textiles, aligning with the goals of cleaner production and sustainable resource utilization.