A hierarchically porous sponge for stabilized emulsion separation with high filtration flux and separation efficiency

Abstract

Emulsion separation remains a challenge in the oil–water separation field, because it is extremely stable in the liquid medium. The main difficulty is that the filtration flux and separation efficiency are not satisfactory. In order to solve these problems, we design a sponge with hierarchical pore structures by a one pot click reaction. The experiments show that large pores in the sponge can improve flux, and the small pores can intercept or adsorb emulsion droplets. Meanwhile, separation efficiency was improved by multilayer filtration through the sponge. Compared with the single macroporous sponge, the advantage is that it can separate stabilized water-in-oil and oil-in-water emulsions with ultrafast separation flux (∼4000 L h⁻¹ m⁻²) and high efficiency (∼99%). The sponge also has good reusability and adaptability to harsh environments (high and low temperatures and strong acids and bases). For silicone sponges, the preparation of hierarchical pore structures is also a breakthrough. The construction of hierarchical pore structures may provide inspiration for separation science.