Amphibious superamphiphilic polystyrene monolith with underwater superoleophilicity: Capture of underwater oil

Abstract Three-dimensional porous polystyrene monolith was fabricated by emulsion templating and it showed superamphiphilicity in the air by absorption of both water and oil droplets rapidly (within seconds). When as-prepared polystyrene monolith was immersed in water, similar behaviors were observed, demonstrating its amphibious superamphiphilicity. In underwater environment, the monolith can be easily filled with water which can be completely displaced by oil as contact with oil droplets, referred to as underwater superoleophilicity. Those interesting properties can be attributed to high porosity provided in emulsion templating and the hydrophilic and oleophilic domains which remain at the interface of interconnected pores after polymerization. The as-prepared monolith was able to absorb at least twenty types of solvents and the maximum uptake capacity was comparable to the performances of other polystyrene absorbents. Moreover, the absorbing capacity remained unchanged after 10 cycles of water and decane absorption and desorption, indicating its good reusability. With the high affinity toward oil, the monolith was able to remove oil spillage and organic pollutants from water and it can be used as an advanced absorbent for underwater oil capture.