Facile fabrication of water-based and non-fluorinated superhydrophobic sponge for efficient separation of immiscible oil/water mixture and water-in-oil emulsion

Superhydrophobic polymer sponges have attracted considerable attention recently as promising sorbent materials for oil/water separation due to their excellent sorption capacity and high selectivity. Although many hydrophobic modification methods for sponges have been reported, it is still challenging to hydrophobic modification of sponge in green, facile and inexpensive manner. In this study, we reported a facile, non-fluorinated, environment friendly, cost-effective and scalable method for hydrophobic modification of melamine-formaldehyde sponge (MF) with water-based acrylic copolymer/silica hybrid superhydrophobic coating (WPAC). The as-prepared superhydrophobic melamine-formaldehyde sponges (SMF) showed excellent oil sorption capacity towards the various oils/organic solvents, up to 78-172 times of its own weight and outstanding recyclability after 30 cycles of absorption-squeezing-heating. Additionally, the SMF can be utilized as high efficient oil pollutant removal device for continuous oil/water separation with the assistance of a peristaltic pump. More importantly, the SMF was capable of separating both immiscible oil/water mixture and surfactant-stabilized water-in-oil emulsions. By virtue of the merits in fabrication method as well as the advantages in oil/water separation, the as-prepared SMF have a promising application in the field of oil spills treatment and environmental remediation.