Collagen Fibers-Derived Superhydrophobic Foams for High-Performance Separation of Stable Emulsions

Superwetting separation has emerged as a promising alternative to address the environmental problems associated with emulsion wastewater. However, a major challenge for superwetting separation materials is the formation of a rejected phase that inevitably leads to fouling and separation failure. Herein, a novel collagen fibers (CFs)-derived superhydrophobic foam was developed by a facile polyurethane foaming approach followed by poly-(dimethylsiloxane) (PDMS) coating. The as-prepared superhydrophobic CFs foam exhibited a high porosity of 80.21%, a static water contact angle as high as 152.2°, and outstanding oleophilicity with fast oil infiltration (0.03 s). The as-prepared superhydrophobic CFs foam was further applied to the high-performance separation of surfactant-stabilized water-in-oil (W/O) emulsions, including surfactant-stabilized W/O emulsions and mixed surfactant-stabilized W/O emulsions, with a separation efficiency exceeding 99.99% and a separation flux as high as 113.04 L m^-2 h^-1. The high porosity of the superhydrophobic CFs foam ensures the storage of the water phase, thus exhibiting excellent anti-fouling performance and recyclability. This work provides a sustainable strategy for developing biomass-based superwetting foams for efficient emulsion separation.