Versatile superhydrophobic sponge for separating both emulsions and immiscible oil/water mixtures

Much effort in resource recycling and recovery has been devoted to developing durable materials for separation, but their versatility for emulsions and immiscible oil/water mixtures was far from ideal. In this work, a superhydrophobic sponge (MS-EP-APT) was developed using asphaltene (APT), melamine sponges (MS) and polyethyleneimine (PEI) for demulsification and water-oil mixture separation. These three easily obtained materials came from either oil refinement residue or low cost chemicals. The surface wettability , chemical stability, and mechanical durability of the sponge were analyzed to determine its separation potential. This sponge exhibited great separation efficiency for immiscible oil/water mixtures (> 96.0%), surfactant stabilized water-in-oil (W/O) emulsions (> 96.0%) and anionic surfactant-stabilized oil-in-water (O/W) emulsions (> 98.0%). It demonstrated good reusability and salt tolerance even in seawater . The separation mechanisms were proposed to be related to the hydrophobicity , positive charge, and torturous channels of the sponge. These superior performances make our sponge a strong candidate for green manufacturing and engineering in resource recovery and environmental remediation.